Question on probability

Question

I can’t seem to figure This one out.  I feel like it’s easier than I’m making it out to be.  I’m lost though for sure.   Any help is greatly appreciated.

 

In a particular neighborhood of 150 homes, 115 of the homes have children, 60 have pets, and 40 have both. What is the probability that a randomly selected home in the neighborhood will:

a) have children or pet? 
b) have neither children nor pets? 

Answer 1

If you do a Venn diagram:

40 both 

20 just pets

75 just children

15 neither

 

a) P(c) + P(p)

b) 15 / 150