0160. Convert the following binary numbers to decimal:

a. 111

b. 1011011

c. 1111111111

111₂ = 1 * 2² + 1 * 2¹ + 1 * 2⁰ = 2² + 2¹ + 2⁰ = 4 + 2 + 1 = 7

1011011₂ = 1 * 2⁶ + 0 * 2⁵ + 1 * 2⁴ + 1 * 2³ + 0 * 2² + 1 * 2¹ + 1* 2⁰

= 2⁶ + 2⁴ + 2³ + 2¹ + 2⁰ = 64 + 16 + 8 + 2 + 1 = 91

1111111111₂ = 1 * 2⁹ + 1 * 2⁸ + 1 * 2⁷ + 1 * 2⁶ + 1 * 2⁵ + 1 * 2⁴ + 1 * 2³ + 1 * 2² + 1 * 2¹ + 1 * 2⁰

= 2⁹ + 2⁸ + 2⁷ + 2⁶ + 2⁵ + 2⁴ + 2³ + 2² + 2¹ + 2⁰

= 512 + 256 + 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1 = 1023