Find the probablity ?

Question

A jar contains 7 pennies, 8 nickels and 2 dimes. A child selects 2 coins at random without replacement from the jar. Let X represent the amount in cents of the selected coins.

Find the probability X = 10.   Find the probability X = 11.   Find the expected value of X.

Answer 1

Prob( 10 ) = 8/17 * 7/16 <--- two nickels

Prob(11) = 2/17 * 7/16 + 7/17*2/16 <--- one dime and one nickle