Question

The remainder obtained when $(2+2^2+2^3\dots 2^{100})$ is divided by 5 is

• A. 0
• B. 2
• C. 3
• D. 4

Answer 1

The correct option is A

0

The unit digit of $2,2^2,2^3,2^4$ are $2,4,8,6.$ For the next four consecutive terms also have same unit digits and so on. So the unit digit of $(2+2^2+2^3\dots 2^{100})$ is 0. So, the remainder is 0.