a person ' s present age is two - fifth of the age of his mother . after 8 years , he will be one - half of the age of his mother . how old is the mother at present ?
"explanation : let the mother ' s present age be x years . then , the person ' s present age = ( 2 / 5 ) * x years . ( ( 2 / 5 ) * x ) + 8 = ( 1 / 2 ) ( x + 8 ) 2 ( 2 x + 40 ) = 5 ( x + 8 ) x = 40 . answer : c"
divide(subtract(8, add(const_2, const_3)), subtract(divide(const_1, const_2), divide(const_2, add(const_2, const_3))))