What decimal number is represents the binary number 10?

Answer 1

In binary this would be written as 1010. This is because in binary (from right to left) the digits in this number mean:

(0 * 20) + (1 * 21) + (0 * 22) + (1 * 23).

This is equal to (0 * 1) + (1 * 2) + (0 * 4) + (1 * 8), which equals 0 + 2 + 0 + 8, which equals 11 (in decimal).