a type r machine can complete a job in 5 hours and a type b machine can complete the job in 7 hours . how many hours will it take 2 type r machines and 3 type b machines working together and independently to complete the job ?
now d should be the answer . r need 5 hours to complete and b needs 7 hours to compete so 2 r + 3 b will complete 2 / 5 + 3 / 7 or 29 / 35 portion of the job in 1 hour so the whole job will take 35 / 29 hours . . . . = d
divide(const_1, add(divide(2, 5), divide(3, 7)))