CAT 2018 Slot 2 — QA Question 26
IndicesEasy
If N and x are positive integers such that NN = 2160 and N2 + 2N is an integral multiple of 2x, then the largest possible x is
Answer & solution
Answer: 10
Solution
From observation, NN = 2160 = 3232 or N = 32.
Now, N2 + 2N = 322 + 232 = (25 )2 + 232
= 210 + 232 = 210 (1 + 222 ).
Here, (1 + 222 ) is an odd number, hence the higest power of 2 is 10.
Therefore the largest value of x = 10.
Hence, 10.