Ifeshyne:
This is a geometric progression (g.p) with ratio = 2, a = 1 (first number) and n = 64.
we use formula for sum of a geometric progression which is s = a(1-r^n)/1-r


After substituting the values, Final answer has to be in standard form if calculators are not allowed
Something like 2^64 - 1 or even just 2^64

just wishing I can at least see your face. beta pikin

shamecurls:
They did not specify the type of corn. White, Gold or Black.

See what being a Buhari zombie has turned you too...

UHHN! How can a Buhari solve the problem of Recession? This bothers me more!

Ifeshyne:
This is a geometric progression (g.p) with ratio = 2, a = 1 (first number) and n = 64.
we use formula for sum of a geometric progression which is s = a(1-r^n)/1-r


After substituting the values, Final answer has to be in standard form if calculators are not allowed
Something like 2^64 - 1 or even just 2^64

Lovely, but something is missing

femi4:
you still dey argue

Nth term formula is different from Summation formula

You ve been using nth term formula which is wrong

Even if u use sum of terms formula, u will arrive at same answer.

dejt4u:
you are wrong.. It is (2^64) - 1 which is different from 2^(64-1)

my answer;
you definitely need a formula.. This is a GP series of the form 1, 2, 4, 16, 32,...

From the above,
first term, a = 1, common ratio, r = 2,
supply this in the formula of sum of nth term of a GP..
S_n = a(rⁿ - 1)/(r-1) since r > 1

therefore, S₆₄ = 1(2⁶⁴ - 1)/(2-1),
S₆₄ = 2⁶⁴ - 1

Scholar you did well but something is wrong, the sequence is not the square of real numbers, check sir

gaffig:

Scholar you did well but something is wrong, the sequence is not the square of real numbers, check sir

yea.. Thanks.. It shld be something like this; 1,2,4,8,16,32,...

agrovick:


Let me break it down a bit, 2 is the common factor (don't ask me how, I only took an informed guess)
1st square = 2^1-1 = 2^0 = 1
2nd square= 2^2-1 = 2^1 = 2
3rd square = 2^3-1 = 2^2 = 4
4th square = 2^4-1 = 2^3 = 8
64th = 2^64-1 = 2^63



Rotfl! You are one nairalander I will love to meet in person

Wrong sir

dejt4u:
yea.. Thanks.. It shld be something like this; 1,2,4,8,16,32,...

You are blessed

Truth be say, dem no wan give u dat Job

tompat86:

Now they want u to addup from 2「1-1 through 2「64-1
Which is The total number of grains which the board can carry.

I bet to disagree sir, the formula is sufficient cos it adds up all the terms, so using S

tompat86:

Now they want u to addup from 2「1-1 through 2「64-1
Which is The total number of grains which the board can carry.

I bet to disagree sir, the formula is sufficient cos it adds up all the terms, so using S

tompat86:

Now they want u to addup from 2「1-1 through 2「64-1
Which is The total number of grains which the board can carry.

I bet to disagree sir, the formula is sufficient cos it adds up all the terms, so using S64

tompat86:

Now they want u to addup from 2「1-1 through 2「64-1
Which is The total number of grains which the board can carry.

I bet to disagree sir, the formula is sufficient cos it adds up all the terms, so using S[sub]

tompat86:

Now they want u to addup from 2「1-1 through 2「64-1
Which is The total number of grains which the board can carry.

I bet to disagree sir, the formula is sufficient cos it adds up all the terms, so using S

tompat86:

Now they want u to addup from 2「1-1 through 2「64-1
Which is The total number of grains which the board can carry.

I bet to disagree sir, the formula is sufficient cos it adds up all the terms, so using S64[/sub]

tompat86:

Now they want u to addup from 2「1-1 through 2「64-1
Which is The total number of grains which the board can carry.

I bet to disagree sir, the formula is sufficient cos it adds up all the terms, so using S

tompat86:

Now they want u to addup from 2「1-1 through 2「64-1
Which is The total number of grains which the board can carry.

I bet to disagree sir, the formula is sufficient cos it adds up all the terms, so using S

tompat86:

Now they want u to addup from 2「1-1 through 2「64-1
Which is The total number of grains which the board can carry.

I bet to disagree sir, the formula is sufficient cos it adds up all the terms, so using S64 = a(r^n - 1)/(r - 1) is sufficient

Ifeshyne:
This is a geometric progression (g.p) with ratio = 2, a = 1 (first number) and n = 64.
we use formula for sum of a geometric progression which is s = a(1-r^n)/1-r


After substituting the values, Final answer has to be in standard form if calculators are not allowed
Something like 2^64 - 1 or even just 2^64

Ms, can we talk maths off nairaland?

Dpearlz:

You're correct. Solving that equation gives 2^63.

It is not correct, there is a little Kinkinli mistake in the formula

wristbangle:


Even if u use sum of terms formula, u will arrive at same answer.

No you won't

Is 2⁶⁴ - 1 same as 2⁶³

Longman6:
Ms, can we talk maths off nairaland?

Chai opportunist, stay ON nairaland

All Mathematicians in the house, well put.

Simply solved by using Sum of GP formula:
Where a=1, r=2, n=64, Total Grains of rice=? Note: Sigma means 'sum up'

n-1
Sigma (ar^n)= a(1−r^n)/(1−r)
k=0

Substitute for the variables

(1*2^64) = 1(1-2^64)(1-2)

Cross multiply

(1-2^64) / (-1) = 2^64 - 1

= 18,446,744,073,709,551,615 (460 billion tonnes of rice)

This is not attainable with the little minutes given. Brain Storming.

femi4:
No you won't

Is 2⁶⁴ - 1 same as 2⁶³

not same sir 2^3 - 1 is not equal 2^2 sir, with all due respect

MRBODMAS:
All Mathematicians in the house, well put.

Simply solved by using Sum of GP formula:
Where a=1, r=2, n=64, Total Grains of rice=? Note: Sigma means 'sum up'

n-1
Sigma (ar^n)= a(1−r^n)/(1−r)
k=0

Substitute for the variables

(1*2^64) = 1(1-2^64)(1-2)

Cross multiply

(1-2^64) / (-1) = 2^64 - 1

= 18,446,744,073,709,551,615 (460 billion tonnes of rice)

This is not attainable with the little minutes given. Brain Storming.

the final answer is very correct but the formula should be that with condition of r>1 sir. Cos r=2

gaffig:
not same sir 2^3 - 1 is not equal 2^2 sir, with all due respect

I guess you quote the wrong person

femi4:
I guess you quote the wrong person

OK sir, oh I guess you were also trying to correct the person..

gaffig:

Chai opportunist, stay ON nairaland

Hello Mr, i don't know what your thoughts were when you called me an opportunist, i will suggest you stop speculating.Regards

gaffig:

Wrong sir

Definitely not wrong, the right word should be incomplete. I did only the 64th term without doing the summation of all the terms.

gaffig:
OK sir, oh I guess you were also trying to correct the person..

yes

agrovick:


Definitely not wrong, the right word should be incomplete. I did only the 64th term without doing the summation of all the terms.

My bad, you were not wrong I was, thank you for the polite response

Longman6:

Hello Mr, i don't know what your thoughts were when you called me an opportunist, i will suggest you stop speculating.Regards

Well, na Joke I dey, no thoughts.

gaffig:
My bad, you were not wrong I was, thank you for the polite response

Respect baba, you are too much.

gaffig:

Well, na Joke I dey, no thoughts.

lol

In general, following some people's comment on how they'll just go home if the job is worth 0<salary<50k, in reality they won't, it only takes a deeper thinking to get it right.
Albeit, preparation also helps. I'll advice my mates looking for corporate jobs to try and practice GMAT frequently, it help the mind sharp when it comes to problem solving during recruitment process, I pray and hope one day this country of ours will be in order.

LastMumu:
What's with the whole interest in corns and grains? If I were you, I would have asked the recruiter if he was a fowl in his previous life.


lastmumu

I.don't want to call you mumu shaa as your name implies. You cracked me up

LastMumu:
What's with the whole interest in corns and grains? If I were you, I would have asked the recruiter if he was a fowl in his previous life.


lastmumu

heheheheheehehe

very funny.

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Originalsly:
I'm sure you didn't get the job.... and all those commenting so far would not have either.Five minutes to do what? .... what was presented to you was not to test your Maths but to test your comprehension. You were given five minutes to say how much you want to be paid... not to calculate how many grains of corn would be on the chess board. That was an indirect answer the chess inventor gave.... you could've done the same by saying the same as the pores on the interviewers body... or more appropriately... just give the salary you want.

this is the right answer....