Please help me solving the following questions:

A prize is randomly placed in one of 13 boxes, numbered from 1 to 13. You search for the prize by asking yes-no questions. Find the expected number of questions until you are sure about the location of the prize, under each of the following strategies.

- An enumeration strategy: you ask questions of the form
'is it in box k?'.- A bisection strategy: you eliminate as close to half of the remaining boxes as possible by asking questions of the form
'is it in a box numbered less than or equal to k?'.