Question 96943
Let the present age of Jennifer's father be x
therefore Jennifer's present age = x/4

In twelve years Jennifer's age = x/4 + 12

15 years ago Jeniffer's fathers age was 

x-15

Since both these ages are same
=> x/4 + 12 = x-15
Transpose the similar terms together
x - x/4 = 15 + 12
3x/4 = 27
Multiplying by 4/3 on both sides

x= 27* 4/3 =36 
Jeniffer's father's age =36 
Jeniffer's age = 36/4 = 9