Answer:
Jenny earns $36 in interest per year.
Step-by-step explanation:
1200/ 12 = 100
3% of 100 is 3.
3 x 12 = 36
So the ratio of boys to girls is 12:24.. now, is that an equivalent ratio as 2 boys for 4 girls? or 2:4? let's see.

you could start simplifying the 12/24 fraction by dividing by some common multiple, say 2, and get 6/12, then divide by 3 and get 2/4 and stop there.
then you'll notice that 12/24 is really 2/4 in disguise.
P(Face card) =16/52 = 4/13
P(Spade) = 13/52 =1/4
P(Face ∪ Spade) = 4/13 + 1/4 = 29/52 = 0.557