This qc bugged me for a couple of hours

[KBTA]

PLEASE CHECK AND ASSURE ME.
n/4+r/8=s/8+t/6
=> (2n+r)/8=(3s+4t)/24
=> 2n+r=(3s+4t)/3
=> 2n+r=1/3(6s+3t-3s+t)
=> 2n+r=(2s+t)+(t-3s)*1/3
=>Column A=Column B+(t-3s)*1/3
Now t-3s may be +ve or -ve. so. A may be greater than or less than B. So, it's definitely D.


Regards,
Jakir

[rohit_oberoi]

Originally Posted by KBTA

PLEASE CHECK AND ASSURE ME.
n/4+r/8=s/8+t/6
=> (2n+r)/8=(3s+4t)/24
=> 2n+r=(3s+4t)/3
=> 2n+r=1/3(6s+3t-3s+t)
=> 2n+r=(2s+t)+(t-3s)*1/3
=>Column A=Column B+(t-3s)*1/3
Now t-3s may be +ve or -ve. so. A may be greater than or less than B. So, it's definitely D.


Regards,
Jakir

Very nicely explained

[polkaparty]

Originally Posted by ayman

Multiply both sides of the equation by 8 and you will get:
2n + r = s + (4/3)t
So the question is now a comparison between:
A) s + (4/3)t
B) 2s + t

This line of reasoning gives the fastest solution I think. Simplify the comparison even further:

Subtract s from both sides to get

A) (4/3)t
B) s + t

Now subtract t from both sides to get

A) (1/3)t
B) s

Now the answer is clearly D since t and s can be any positive integer.

[econ_phd_2009]

well explanation, Jakir .