A father is four times as old as his son now. If 5 years later the father is 3 times as old as his son's age. What are their present ages

Answer:The Present age of father is 40 years  The Present age of son is 10 years Step-by-step explanation:Given as :Let the age of father = F yearsThe age of son          = S yearsAccording to question F = 4 × S                     ......... 1And   ( F + 5 ) = 3 × ( S + 5 ) F + 5    =  3S + 15 Or,   F - 3S = 15 -5Or,   F - 3S = 10                ......... 2From Eq 1 and Eq 2       4S - 3S = 10 ∴      S = 10 years Put the value of  S in eq 1So ,  F = 4 × S   = 4 × 10 ∴      F = 40  years Hence The Present age of father is 40 years  And      The Present age of son is 10 years    Answer