1/a + 1/m + 1/z = 1/2
so,
1/5 + 1/6 + 1/z = 1/2
1/z = 2/15
1/a + 1/z = 1/5 + 2/15 = 1/3
so, Ann and Zack take 3 hours to do the job together.
Ann, Matt and Zack are working for a cleaning company. Together, they can clean a house in 2 hours. If Ann does the job alone she can finish it in 5 hours. If Matt does the job alone he can finish it in 6 hours.
How long will it take Ann and Zack together to finish the job?
1 answer