in 10 years , a will be twice as old as b was 10 years ago . if a is now 6 years older than b the present age of b is
"let present age of a be a and b be b a + 10 = 2 * ( b - 10 ) = > 2 b - a = 30 . . . . . . ( i ) a = b + 6 = > 2 b - b - 6 = 30 b = 36 so the present age of b is 36 years answer : b"
add(add(multiply(const_2, 10), 10), 6)