Question

Five years ago Pooja was twice Sachi’s age. Five years hence, their age will be in the ratio 4:3. Find their present age

Answer 1

P-5 = 2(S-5)

P = 2S - 5

2S - P = 5…………(1)

then 5 years hence

P+5 / S+5 = 4/3

3P+15 = 4S+20

3P-4S = 5…………(2)

Adding 1 and 2

2S - P = 5
-4S + 3P = 5

mul. First with 2
we get 4S eliminated
-2P = 10
+3P = 5

then we get P = 15 and put this in any of the (1) or (2) and we get S = 10