In the year 1988 , Q's age is 3 times of P's age . R is 25 years younger than Q . In 1995 , S's age is a quarter of P's age . In 2004 , S is 21 years old . How old is R when S was born ?

In 1988 , Q=3P

R=Q-25

In 1995 ,

In 2004 ,

S=21 --- S will be 21-9 = 12 in 1995 .

P is 41-7=34 years old in 1988 .

Q=3(34)=102 years old . Hence , R=102-25 =77years old .

In 1988 , S was 5 years old .

SO when S was born , R=77-5=72 years old .

It is wrong .. Where is my mistake ? Thanks