text: calling all ye math experts? the mum is 21 years older than the child.  in 6 years from now the mum will be 5 times as old  as the child.   question : where's the father? let the child be 'x' years old right now. so the mum must be x + 21 years of age. so, after 6 years the mum will be x + 21 + 6 = x + 27 years old and the child will be (x + 6) years old at that time. so from the given information we get, 5*(x+6)=x+27 therefore, 5*x+30=x+27 therefore, 4*x=27-30 therefore 4*x=-3 therefore x=-3/4 but -3/4 years = -3/4 * 12 months i.e. the child is -9 months right now. this means the child is just getting conceived. hence the father of the child must be in bed with the mum right now!