₦airaland Forum

The number of 4 digit even numbers that can be formed using 0,1,2,3,4,5,6 without repetition is
A) 120
B) 300
C) 420
D) 20
E) 42


RichyBlack, edusegzy, hollandis and others, pls explain how

to solve this. I'm utterly confused. Would I ever understand permutation

and combination?

yeah, you are right edusegzy. The answer is surely three.

The number of 5 digit telephone numbers having atleast one of their digits repeated is
A) 90000
B) 100000
C) 30240
D) 69760
E) 69000



How would you solve this?

U guys are doing a good job proferring solutions.

edusegzy, kudos man!

edusegzy,

Welcome back!!! Your solution was right. Well check out this question:

An identification code read from left to right consists of 2 digits, a dash, 3 digits, a dash, and then 4 digits. Each digit can be any number from 0 through 9.

A) The number of different identification codes possible.

B) 10^9

edusegzy,

Where you at ? Your estimable inputs are highly solicited.

Straighthen out of your state of doldrums and come assist in

keeping us going sprightly. Hope to read your post soonest.

@RichyBlack,

Kudos man for that great math score. The scaled percentile of 99 shows that you were

high up there in the test-tester's pool. I can infer that you've got a knack for math.

Yeah, I'm about to write the GRE in a month's time, precisely in 30 days time. There's an area in math that

I never understood when I was in high school and I'm still finding it difficult getting even now.

Thats the area of combination and permutation. Questions from this area flusters me utterly. The reasoning

behind such questions always go beyond my cerebration unnoticed. Maybe you can help here. Doffing my cap for you

in acknowledgment of your stock math predilections, can I count on you in this regard to put me through the underpinnings

of this concept of recondite attribute as I seem to be continously wallowing in this combinatorial and

permutational impasse? Other areas are quite surmountable. They are more like taking candy from a baby!

Most questions I'll be posting will be from this area and I hope I'll get useful explanations from the math prodigies on nairaland.

Meanwhile, I've corrected the question I earlier posted. Hope to get solutions. Others with questions should bring them here so we

tender solutions and compare approaches. I feel this is going to be helpful as it strengthens and expands one's problem solving abilities. Let's keep

posting questions and proferring solutions.

@ RichyBlack,

Yeah, I didn't notice it. There was a mistake and it has been corrected.

A bag contains 5 one dollar coins, 4 fifty cent coins, and 3 twenty cent coins. A boy

is asked to take 2 coins at random from the bag as his birthday gift, what is the probability of the boy drawing the maximum possible amount?

a) 5/33 b) 11/66 c) 1/6 d) 5/12

@ RichyBlack,

Was that the only book you used for preparation?

I've got the smaller version of the BIG BOOK with 9 test.

I learnt the bigger version one has 27 .

The math there is too simple. That can't be actual GRE

questions. The real GRE is more tasking there wrt quant.

The verbal is at par with the real GRE. The BigBook boots confidence a lot.

What was your quant score like?

Who is a "longathroat" then? While the words I posted may not be perfect synonyms

which is rarely the case in plebeian diction, I do believe that contingent on the content in which

they are used, they could synonyms.

I posted those words based on the assumption that "longathroat" transliterated, means

-to eagerly want something;

-to want to get everything you are giving to the last piece ( often in a waggish and grotesque manner);

-to be stingy, in that you always want people's things.

I hope I have cleared any doubt whatsoever you had. If not, we can etymologically reason out why

those words fit probably not perfectly but certainly within the gamut of the word's grammatical use.

Why is this thread kind of dormant? Do some brainstormings, men and be kind to post the upshot here.

Well, let's move on.

A candidate who gets 20% in an exam fails by 30 marks and the other candidate who gets 32% gets 42 marks more than the pass mark. Find

the pass mark in percentage.

a) 20% b) 25% c) 30% d) 40%

Oops ( scratches his head)!!! Been a while, dude. I need to dust off my linear Algebra Text from the shelf.

My cerebration on eigen values is quite seedy and hazy. Be right back!

edusegzy


Great work buddy. Where did you write the GRE? How difficult or should I say, challenging was the quant section? How did your friend

prepare for the GRE verbal? Men, you just need to help in my preparation.In fact, can you give an epical account of how you prepared for the test

and your impression of the difficulty index? The GRE is a linchpin in my application as it would really help me in determining where to apply. I've

got 34 days left. I need tips man. Those scores you quoted,1520, 1600/1600, they are really sources of inspiration!Kind of dream scores, though

achievable of course! I'm highly motivated. Ask you friend to bare the secrets to such an atronomical score . I really need to score high.

Actually, I'm not studying in Nigeria. I'm currently in my senior year in Russia. Hopefully shall be a Ph.D student come fall'08. I'll keep you

posted as time passes. Shall be applying to top 10 in my field and probably 2-3 safe schools--it'll all come down to the upshot

of the GRE exams. After the GRE, I'll have a ready list then.

Hope to read an account of your GRE experience and those of other GRE overachievers you've come across. They'll be greatly invigorating!

This is another GRE question:

A vending machine dispenses gumballs in a regularly repeating cycle
of ten different colors. If a quarter buys 3 gumballs, what is the
minimum amount of money that must be spent before three gumballs of the
same color are dispensed?

(A) $1.00
(B) $1.75
(C) $2.00
(D) $2.25
(E) $2.50


Please explanations are needed on how to get the correct answer.


[color=Black] SPOILER: B[/color]

A number is divisible by 9 if the sum of its digits

is divisible by 9.

As an example,

The sum of the digits of the number 63 is:

6 + 3 = 9.

9 is divisible by 9.

Hence 63 is divisible by 9 or you can say,

9 divides 63.

These shortcuts are really vital in time-constraining exams like the GRE, GMAT and job-recruiting aptitude test.

They can save you valuable amount of time and you can eschew clumsy calculations if you endear them dotingly.

Divisibility criteria for 6 and 9

A number is divisible by 6 if that number is divible by 2 and 3.

Since we know the divisibility criteria for 2 and 3, then it'll always be

a facile task to discern if 6 divides a number or not.

As an example,

395 384 706 is divisible by 2 since the unit digit of the number is 2.

The number is also divisible by 3 since the sum of its digits ( 3 + 9 + 5 + 3 + 8 + 4 + 7 + 0 + 6 = 45 ) is divisible by 3.

=> 395 384 706 is divible by 6.

395 384 706 / 6 = 65 897 451

@ edusegzy

Well, the question is an actual GRE question.A friend got it as one of his question while he was writing the GRE. He couldn't remember the options.

Yeah, I will sure make my own inputs on this thread. This is a nice thread you started.

More is on the way. Shall be posting questions for people to solve.

I've got a databank of actual GRE questions from friends who wrote it over the past 2 yrs.

Hope it'll be of help to future GRE writers and me too as I prepare for the exams coming up in about 34 days time.

Edusegzy, you seem to know some stuff about the GRE? Have you written it in the past?

Any preparation tips for Verbal and the Quant section?

RichyBlack, Your suggestion on the GRE would be winsomely welcomed. I'm sure

they are going to be really sagaciously enrapturing.

Nairalanders, please show yourself and let the thread keep prodding on vehemently.

@ RichyBlack,

Men, your ingenuity baffles me. I've been grappling with this problem for about 3 days. Just arrived at a definitive solution while I was sleeping .I woke up immediately to come post the solution I reasoned only to see some detailed and vivid logical explanation to the problem by you.

That implies this form is visited by people with ready wits. Kudos RichyBlack [/b]for that great explanation. Thats an indelible impression you've created on me.
Hopefully, we'll get more of such from this forum.

Well, I used combinatorics to arrive at my final answer.

The number of //ograms formed would be:

[b]6C2 * 5C2 = 150.

Explanation

There are 6 // lines crossing 5 // lines.

A //ogram is formed by 2 opposite // lines and by 2 other opposite // lines.

The 6 // lines would form 2 of the opposite sides of each //ogram while the other 5 // lines would
form the other two opposite sides.

2 opposite sides of the //ogram can be chosen from 6 // lines in 6C2 ways.

The other 2 sides can be chosen from the 5// lines in 5C2 ways.

In all, the total number of //ograms that will be formed would be:

6C2 * 5C2 = 15 * 10= 150.

$500 for TOEFL? Great hoodwinking by Touche !!! Sorry for being treated that harsh.

Next time, you'll show them you can gull them.

The answer is far more than 20. The number of parallelograms is much. I hope I'll get a candid explanation.

I tried solving it using combinatorics but my reasoning seems specious.

Well, for the GRE, been grappling with words for some time now. The quant if not for some technicalities,

I'll say it's ok.

Men, edusegzy, this is a great Job u r doing. Let's keep it rocking!

Sorry, I made a mistake in the question. The correct question is:

Six parallel lines cut each of the other 5 parallel lines. Find the number of different parallelograms formed.

Great job edusegzy! Those are very useful tips you are bringing to light. This will really help me in my GRE preparation. I've got lots of unanswered questions buddies.

One of them is:

Six parallel lines cut each of the other 5 parallel lines. Find the number of different parallel formed.


I'll also help in answering some of your question if I can and I look forward to seeing

the solution to the above question.

I'll post some problems of quant level 800 later so you have a feel. If you know anyone who wrote the exam, ask them to tell you some of the questions


they can remember. You post them here so we can benefit too.

These are actual GRE Quant questions . They are of difficulty level between 650 and 750.

1. (x+2)^(x+2)<-1


Column A Column B

X -1



2.What is the probability of picking 12 soldiers from a camp of 15 soldiers if 5 soldiers are injured? - The guy I that sat beside me got this as his first question.



3.In 1979 the average homeheating cost in central region was same as the average for entire country, in 1980 central average cost increasd by $260 per home, an increase of 25% over 1979. If in 1080 average cost of of entire cntry increased by 22%, wat was average increase in cost per home for entire country?

A. 57.2

B. 65

C. 228.8

D. 317

E. 325


4. On a certain scale of intensity, each i ncrement of 10 in magnitude represents a tenfold increase
in intensity. On this scale, an intensity corresponding to a magnitude of 165 is how many
times an intensity corresponding to a magnitude of 125?
(A) 40
(B) 100
(C) 400
(D) 1,000
(E) 10,000


5. A vending machine dispenses gumballs in a regularly repeating cycle
of ten different colors. If a quarter buys 3 gumballs, what is the
minimum amount of money that must be spent before three gumballs of the
same color are dispensed?

(A) $1.00
(B) $1.75
(C) $2.00
(D) $2.25
(E) $2.50

6.Two trains 100 m and 150m in length long are going in the same direction on parralel tracks.Faster train speed is 60 kmph and slower train speed 42 km ph.At what time does faster train overtake the slower train?. I've forgotten the option but I know the answer.


7. k is a positive integer. The function f(x) is defined as:
f(x)= remainder when x is divided by k.
What is the value of k , if f(k+25)=3.

Well, I don't know about GRE centres in Abuja. But I do know that the GRE now cost $170 for registration. In one of the post, you said someone posted you a GRE CD from abroad. Why not tell the person to register you using his credit card and online via ETS.But if you've got a credit card, better. When you register, you'll be sent an e-mail and there you'll find all you need.The location of the centre, the rules, ur reg number and others. Men, holla. Maybe we can prepare together. Which CD were you sent?

Guys, great to see that people are preparing for the GRE . We can make this forum very interactive. Well, if you are just starting your preparation and
you are aiming for as high a score as possible, I think 6-8 weeks is enough to work out a definitive plan on how to prepare for the GRE. Depending your
background, I'll advise tackling the vocabulary section first: I am assuming you have strong math skills and have got at least 6 weeks for preparation.
This was how I prepared for the first trial. I'll be writing again ending of next month. I was short on time- I had barely three weeks. I designed a very
grueling schedule. I used the Barrons for my preps. The Barron has won the confidence of many including me.In my real test, all the words I encountered were Barrons.It is still one of the best preparation material out there. It has about 50 wordlist with about 70 words in each wordlist (WL). So the WL is normally adverted by GRE aficinados as "The GRE 3500 Hit Parade". As this is a GRE forum, I'll suggest we always be on the GRE mode when we are here and use GRE cants to make the forum very engaging.
My grueling schedule was such that I studied the 50 WL in 15 days. I sedulously perused through 3-4 WL per day and with great assiduity and application that, by the 16th day I was through with the List and with an impressive 70% retention.But this is not the best method. I feel it is better to tackle it at your pace. You devise your own technique and work with it religiously.The remaining 7 days I used for practice and it helped inculcate the words deeper and also revealed that I had Reading Comprehension(RC) as one of my foibles. As there was not enough time, that costed me some huge marks on the Verbal.
For math, being an Engineering major, I thought that was going to be a zephyr ( yeah, I'll use this word here ) . I was wrong. I got flailed by GRE quant. Friends, don't underrate the quant. If really you want a very high score on the quantitative section, then you must not underrate this part as it might cost you some valuable points even if it is 10-20 which might be a touchstone in determining if you are getting an admit or not. So I'm of the contention that we should use this forum to sharpen our math skills. Whenever I come across actual GRE math questions, I'll post them here for solutions to be tendered and for us to get a feel of the difficulty index of the GRE.Questions are repeated on GRE often.
I'll be writing the GRE in about 35 days time from now. Having gone through the Barrons WL superficially once, I'm doing it for the second time though this time conscentiously, 2 WLs/ day. Come on, dudes, I'm sure we can work together via this forum. Though the GRE is not the single most important factor on your graduate application and sure not a means to an end, I aver that it is highly weighted especially for those of us from countries where it is quite difficult for the admission committee to comment on our educational standards. So the GRE becomes a factor to be used to compare academic achievements of different applicants as they claim it is a standardized test.
Well, I'll update this thread later but I hope we could work together and share opinion on how to crack the GRE. I've got some e-materials. If you think it would be of help to you, then let's interact via this forum and I'll send it across to you. Wishing you all the best as you diligently prepare to your prep heyday and finally unravel the mysteries to an GRE 1600 on the D-day. Bravo!

longer throat in Nigerian has got multifarious meaning depending on the context.

It can mean Covetous
Desirous
Avaricious
Yearning

Rapacious
Penny-Pinching and much more.

check out the contect it is being used then the meaning will be blatantly glaring.

Where the guys preparing for the GRE? Come let's share ideas on this forum. I took the exam about a week ago and got a very low score. Preparing to retake it in october. The stuff aint that tasking, it's just the timing that gave short-breathed me. We need ideas on this forum men on how to crack this so called GRE and raise our scores!

Hi,
Howdy! I'm also preparing for the GRE. So what are you up to? I'll be writing TOEFL in september and GRE anytime from now.I've been preparing for some days now and the verbal part has really been nerve-wracking. So whats up? You plan on using the scores for fall'08 admission.Come on, lets study together via this forum. Let me know how u intend to crack the verbal part of the GRE-thats a real hurdle to cross; as an engineering undergrad, the quantitative section has been going smoothly.
Holla and let's make this thread interactive!

@enolase ,
Thanks for the correction. I'm not that good with spellings. All the same, the correction's appreciated.
I can now tell the difference between those words.