question of weight

Let A kg be the present weight of Amy;
--> so, A/1.6 kg was the weight of Amy 5 years ago.

A-4 = A/1.6
1.6 x ( A-4 ) = A
1.6A - 6.4 = A
0.6A = 6.4
A = 6.4/0.6
A = 32/3 kg or ( 10.66667 kg )

Therefore, present weight of Amy is 32/3 kg or ( 10.66667 kg ), and...
5 years ago, the weight of Amy was:

32/3 - 4 = 20/3 kg or (6.66667 kg )


Let B kg be the present weight of Ben
--> so, B/1.6 kg was the weight of Ben 5 years ago.

B-15 = B/1.6
1.6 x ( B-15 ) = B
1.6B - 24 = B
0.6B = 24
B = 24/0.6
B = 40 kg

Therefore, present weight of Ben is 40 kg, and...
5 years ago, the weight of Ben was:

40 - 15 = 25 kg