Nely77:

Go to school if you have not been to school. If you had been to school, then go back there and learn because you have learnt nothing since you cannot solve basic math's.

Laive:
Too many critics, so I had to remove the thread. All the same, I HAVE LEARNT THE RIGHT WAY OF DOING IT. Thanks!

Damfash:
Q9a. I'll try to make the solution very simple. Let the two-digit number be XY. X is the tens digit while Y is the unit digit. X=Y+5........(i). Note: A two-digit number is ten times the tens digit plus the unit digit. E.g 54=(5*10)+4, 63=(6*10)+3. Let's proceed! (10X+Y)+14=3*X*Y. So, we have 10X+Y+14=3XY........(ii). Sub. equation (i) into equation (ii). 10(Y+5)+Y+14=3Y(Y+5)... 10Y+50+Y+14=3Y^2+15Y.... 3Y^2+4Y-64=0. Y=4 or Y=-5.33. Discard the second value. If Y=4, X=Y+5=4+5=9. The two digit number is 94.@ Wealthgang

Ifeconwaba:
I hate mathematics

Horlawale1:
Am a big lover of mathematics, but lately am losing interest.

Sincere question, how can this be use to solve economy situation, or how is this applicable in real life.

While some School Cert holder are discovering new inventions in China, we are here looking for 'X'
Who X help

Nigeria education sector needs review.
My opinion

Horlawale1:
Last week a first class holder in mathematics is still looking and crying for job on this forum.

And some ppl are still looking for a guru to come solve some abstract disturbing Mathematics.

Money making on my mind.

Xflint:
7b) solution

Log(x² + 4) = 2 + log^x - log²⁰
log(x² + 4) = log¹⁰⁰ + log^x - log²⁰
log(x² + 4) = log (100 X x)
                              20

Now, you cross multiply
given you 20(x² + 4) = 100 X x
20x² + 80 = 100x

now divid by 20
20x² - 100x + 80 = 0
20         20      20


x² - 5x + 4 = 0
x² - 4x - x + 4 = 0
(x² - 4x)(x + 4)
x(x - 4) -1(x - 4)
(x - 1)(x - 4)
x = 1 or 4

the strike is not working here just check
http://forum.mathsboard.com/t594-solve-this-neco-past-questions-2016-2017#1517
[s][/s]

nwadiuko1:
Jesus I hate mathematics, can we have a thread where we solve questions for accountancy, economics and banking and finance students?

Kaybee7000:
N=3 or 1 Mr man

ENIGMA24:
at least if not for any major reason u need to pass maths in waec or neco to forge ahead academically else u get stuck and join the nigerian police force with your o'level .. ... U pefer to collect #20?

Wealthgang:
Check Out The Recent NECO Math Questions Some School Teachers Couldn't Solve


Same order they appeared in d question paper.

Q3) A man is 5 times older than his son. Four yrs ago, d product of their ages was 448. Find their present ages.

Q7a) Find d value of n if
3²ⁿ⁺¹ - 4(3ⁿ⁺¹) + 9 = 0

7b) Solve d eqn:
log(x²+4) = 2 + logx - log20

Q9a) A two-digit number is such that its tens digit is greater than its unit digit by 5. If d number is 14 less than 3 times d product of its digits, find d number.

Let's see how many Nairalanders can give it a shot. Anyone who answers correctly will get a reward.

Cc: Xflint, Boyoski09, truth12, themall, Danosaur007, Jerrypolo, 8BitGee, integritylady, Laive, lilmonarch

heskeyw:
I studied marketing bt I will gv it a shot.
Solving
A man is 5 times older than his son
Mathematically
Let d son's age be x.
Papa age (since he's 5times older) = 5timesx which is 5x.

Four yrs ago, d product of their ages was 448
Mathematically
X times 5x = 448
»5x2(square) = 448.
X2 =448/5
X2= 89.6
X = square root of 89.6 which is 9.46
Therefore, the son's age is 9.46yrs while the papa is 9.47 times 5 which is 47.35yrs.

Ka odi banu.

InfomejobsN:
Which School Teachers Couldn't Solve this?

cosmic22:
calculating for 4 years ago

man-5x

son-x

product of ages

5x * x = 448

5x squared = 448

x squared=448/5

x = √89.6

x = 9.465 ( boys age )

(fathers age) 5x = 47.325

calculating present ages

approximate ages

9 + 4 = 13 years old (boys age)
47 + 4 = 51 years old ( fathers age)

AnonyNymous:

Dude to build a robot you require knowledge in Mechatronics engineering. . . Even common mesh/node analysis requires math, and finding 'x'. Without math all the inventions people are making in other countries would not have existed. Rather, the reform Nigeria needs is to fund practicals and research in universities

Musquareney:
Q3) son= 12 and father = 60

Q7a) n= 0 or n= 1

Q7b) x= 1 or x= 4

Q9a) the number is 94

Where are my gifts

philipobiz:
Q3. The man's age 4yrs ago was 448÷5= 89.6.
His current age is 89.6+4=93.6.
Since he is 5 times older that his son 4yrs ago. The son's age was 89.6÷5= 17.92. Therefore, his current age is 17.92+4= 21.92.
The man's current age = 95 yrs 6 days
The son's current age = 21yrs 92days

Joice21:
Four years ago; son's age=x-4, father's age=5x-4. Now, product of their ages four years ago= (5x-4)(x-4)=448. Expnsion of the bracket gives:5x^2-24x+16=448 and this equals 5x^2-24x-432=0. Now following the a x c formula to expand b,a=5,c=-432,b=-24, a x c=5 x -432 =-2160. Look for two numbers such that when u multiply u get -2160 n wen u add u get -24, the two numbers are -60 and 36. Now d equation above becomes: 5x^2-60x+36x-432=0, when u group and find the common factor, u get 5x(x-12) + 36(x-12)=0, (5x+36)(x-1

Joice21:
Four years ago; son's age=x-4, father's age=5x-4. Now, product of their ages four years ago= (5x-4)(x-4)=448. Expnsion of the bracket gives:5x^2-24x+16=448 and this equals 5x^2-24x-432=0. Now following the a x c formula to expand b,a=5,c=-432,b=-24, a x c=5 x -432 =-2160. Look for two numbers such that when u multiply u get -2160 n wen u add u get -24, the two numbers are -60 and 36. Now d equation above becomes: 5x^2-60x+36x-432=0, when u group and find the common factor, u get 5x(x-12) + 36(x-12)=0, (5x+36)(x-1

emsheddy:
Am telling you bro! It didn't take me up to an hour to trash all the neco theory questions for my students in SS 2! Any maths teacher who can't solve those questions is not fit to be called a maths teacher! By the way, make una employ better maths teachers for that una school oh! I won't mind porting to that school if the pay is worthwhile! Cc Wealthgang

Damfash:
Q9a. I'll try to make the solution very simple. Let the two-digit number be XY. X is the tens digit while Y is the unit digit. X=Y+5........(i). Note: A two-digit number is ten times the tens digit plus the unit digit. E.g 54=(5*10)+4, 63=(6*10)+3. Let's proceed! (10X+Y)+14=3*X*Y. So, we have 10X+Y+14=3XY........(ii). Sub. equation (i) into equation (ii). 10(Y+5)+Y+14=3Y(Y+5)... 10Y+50+Y+14=3Y^2+15Y.... 3Y^2+4Y-64=0. Y=4 or Y=-5.33. Discard the second value. If Y=4, X=Y+5=4+5=9. The two digit number is 94.@ Wealthgang

Wealthgang:


Fantastically correct.
This approach is more difficult than using d quadratic general eqn cos it aint easy to think out those two numbers to expand 'b'.
Kudos!

RaggedyAnn:
Common confusion. If you say 5 times OLDER THAN, you expect x-y = 5y therefore x = 6y
If you mean 5 times AS OLD As, then x = 5y
Where x and y are the ages of father and son respectively. Math teachers should learn to state questions correctly.


Annakrutitskaya
Senior Member
Russian
Hello!

I would be grateful for the help - I am confused with underlined explanation. (from Gmat sentence correction)

Right: The man is FIVE TIMES AS OLD AS his grandson.
Wrong: The man is FIVE TIMES OLDER THAN his grandson.

The first sentence means that the mans age = 5 x his grandsons age. In the second example, the author is technically saying that the man is six times as old as his grandson. This meaning is unlikely; the author probably meant “five times as old.”

Why 'five times older than' equals 'six times as old as'?

Thank you!


Annakrutitskaya, Aug 15, 2014 #1

Nely77:

you are totally wrong! Who was your mathematics teacher? He/she did not try at all.

Wealthgang:


Unnecessary pedantry for an O'level question.