a work as fast as b . if b can complete a work in 36 days independently , the number of days in which a and b can together finish the work in ?
"ratio of rates of working of a and b = 2 : 1 ratio of times taken = 1 : 2 a ' s 1 day work = 1 / 18 b ' s 1 day work = 1 / 36 a + b 1 day work = 1 / 18 + 1 / 36 = 3 / 36 = 1 / 12 a and b can finish the work in 12 days answer is a"
inverse(add(inverse(36), multiply(const_2, inverse(36))))