The number of air-conditioning units sold during a week in a particular store in the Parramatta CBD is given below, along with its probability distribution.

X	0	1	2	3	4
P(X)	0.1	0.3	0.3	0.2	0.1

9.What is the expected value for the number of air-conditioning units sold in a week?	A 2.0	B 1.9	C 2.1	D 1.5
10.What is probability that the store sells at least three air-conditioning units in a week?	A 0.7	B 0.1	C 0.3	D 0.2