the age of father 7 years ago was 5 times the age of his son . 5 years hence , father ' s age will be thrice that of his son . the ratio of their present ages is :
let the ages of father and son 7 years ago be 5 x and x years respectively . then , ( 5 x + 7 ) + 5 = 3 [ ( x + 7 ) + 5 ] 5 x + 12 = 3 x + 36 x = 12 . required ratio = ( 5 x + 7 ) : ( x + 7 ) = 67 : 19 . answer : option a
divide(subtract(multiply(5, divide(subtract(add(multiply(5, const_3), subtract(multiply(7, 5), 7)), 5), subtract(5, const_3))), subtract(multiply(7, 5), 7)), divide(subtract(add(multiply(5, const_3), subtract(multiply(7, 5), 7)), 5), subtract(5, const_3)))