What is the greatest prime factor of 2^100 - 2^96?
A. 2
B. 3
C. 5
D. 7
E. 11
What is a good approach to this?
A. 2
B. 3
C. 5
D. 7
E. 11
What is a good approach to this?
IMO a good approach is to extract the common part in both the exponents & then work with the problem, In fact this step will itself present the soln
i.e 2^100 - 2^96?
2^96 ( 2^4- 1)
=2^96(15)
=2^96 (5*3)
ans 5 C
