Question 1199026
Four years ago,a mother was 4 times as old as her son.In 4 years time, the sum of their ages will be 56years .Find the age of the mother when the son was born 
<pre>Since the sum of their ages in 4 years' time will be 56, sum of their ages now is 56 - 2(4) = 56 - 8 = 48.

Four years ago, the sum of their ages was 48 - 2(4) = 48 - 8 = 40. Since at that time, the mother was 4 times
as old as the son, and with the son's age being S at that time, we get: S + 4S = 40
5S = 40
Son's age then (4 years ago) was {{{matrix(1,3, 40/5, "=", 8)}}}, and mother's was, 40 - 8 = 32.
Difference in their ages, 4 years ago, and as long as they're alive: 32 - 8 = 24

With the difference in their ages being 24, the <font color = red><font size = 4><b>mother was 24 when the son was born</font></font></b>.</pre>