Math word problem

Question

A man is ten times as old as his son and twice as old as his daughter. The sum of the ages of all three is 64 years. How old is each person?

Answer 1

m = 10s, s= m/10

m=2d, d=m/2

m+s+d = 64

m+ m/10 + m/2 = 64

10m + m +5m = 640

16m, = 640

m = 640/16 = 40 years old

son =40/10 = 4 years old

daughter =40/2 = 20 years old

40+4+20=64