We can use trial or error method here...
If we take 4 table, 4*5 = 20 and 4*7 = 28. 20+28 = 48.
20 : 28 = 5 : 7
So, there are 20 boys and 28 girls in a school play and there are 8 girls more than boys.
If you look over tables and try it out, only 4 table works for the given ratio.
