if a is thrice as fast as b and together can do a work in 15 days . in how many days a alone can do the work ?
"a ’ s one day ’ s work = 1 / x b ’ s one day ’ s work = 1 / 3 x a + b ’ s one day ’ s work = 1 / x + 1 / 3 x = 1 / 15 = 3 + 1 / 3 x = 4 / 3 x = 1 / 15 x = 15 * 4 / 3 = 20 answer : b"
inverse(divide(const_3, multiply(15, const_4)))