Answer:
45 songs in one year (12months)
Explanation:
in one year she will have the following
12 x 3 = 36
+ 9 given
36+9 = 45 songs in one year
if it was decreasing to 11 months or 10 months etc
Then we use this formula
Birthday + (Amount monthly x No of month)
9 + (3 x 11) = 42 in 11 months
or 9 + (3 x 10) = 39 in 10 months