1/2+1/4+1/8+1/16

Get a common denominator, which is 16, then change each fraction to 16ths.

1/2 + 1/4 + 1/8 + 1/16 =
8/16 + 4/16 + 2/16 + 1/16, then add all the numerators to obtain 15/16 for the answer. Check my work.