10101 2 to base 10 is:

Question

1:21
2:12
3:20
4:13

Answer 1

The correct answer is 21.

(1 x 2^4) + (0 x 2^3) + (1 x 2^2) + (0 x 2^1) + (1 x 2^0) = 16 + 0 + 4 + 0 + 1 = 21