Question

If you select a month at random from a leap year, what is the probability that the selected month will have an even number of days?

Answer 1

5/12

Explanation:

First, list the months by the number of days each has:

Jan: 31, Feb: 28 or 29, Mar: 31, Apr: 30, May: 31, Jun: 30, Jul: 31, Aug: 31, Sep: 30, Oct: 31, Nov: 30, Dec: 31.

How many of these 12 months have an even number of days?

Feb, Apr, Jun, Sep, Nov (assuming that we ignore Leap Year): 5 months

Then the probability that the selected month will have an even number of days is

5 months

--------------- = 5/12

12 months