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# will be divisible by  a)25b)8c)7d)3Correct answer is option 'C'. Can you explain this answer? Related Test: WBJEE Mathematics Sample Paper II

## JEE Question

 Prem Kurakula Oct 05, 2020

 Rashid Dar Oct 05, 2020
Put the value of n =1.The answer comes 8 - 1 = 7. then divided 7 by 7 the answer comes 1it means 7 is the correct answer.

 Prasanth Chinteryala Oct 26, 2020
7

 Subas Oct 26, 2020
To answer it in a simple,
Just substitute some value to 'n'
Let's say n=1,then
(2^3(1)-1) gives 7 which can only be divided by 7 and there we go! ! !

 Pratyush Kumar Kumar Dec 10, 2020
Put n= 1 which is equal to 2³-1=7
therefore we can say that it is divisible by 7
you can also check for other values of n

7 is the correct answer , because
when 2*3n-1
=. n=belongs to real numbers can take an number you want
let's take n=1
now, 2*3(1)=1
2x2x2-1=0
8-1=0
7

 Srinivasulu Yendikatla Y Jan 21, 2021
As (a^n-b^n) is always divisible (a-b). So ((2^3)^n-1) is always divisible ((2^3)-1) which is 7.

 Rekha Devi 39 minutes ago
7 bez if put n is equal 1 we got 8-1=7 if put n is equal 2 we got 64-1=63 which is divisible by 7