Answer:
31.8%
Step-by-step explanation:There are 7 months that have 31 days so,
The odds the first selected month has 31 days is 7/12
The next month there are only 6 months left with 31 days of only 11 months to choose from
so the odds for the second are 6/11
To calculate the odds they BOTH have 31 months you multiply the two odds:
(7/12) x (6/11) = 42/132 = .318 so 31.8%
A = 1/2h(b1 + b2)
2A = h(b1 + b2)
2A/h = b1 + b2
b1 = 2A/h - b2
