the difference between the ages of two persons is 11 years . ten years ago , the elder one was twice as old as the younger one . the present age of the elder person is
"let their ages of x years and ( x + 11 ) years respectively . then , ( x + 11 ) - 10 = 2 ( x - 10 ) ⇔ x + 1 = 2 x - 20 ⇔ 3 x = 21 . ∴ present age of the elder person = ( 7 + 11 ) = 18 years . answer : 18 years"
add(subtract(11, subtract(11, add(const_3, const_2))), multiply(subtract(11, add(const_3, const_2)), const_2))