Three machines A, B, and C take 3 hours to do a job, when working together. Machines A and B are identical, and C working along can complete the job in 12 hours. How long would it take A working alone?
+36916 A time = B time
1/a + 1/a + 1/c = 1/3 1/c = 1/12
2/a + 1/12 = 1/3
2/a = 1/3 - 1/12
2/a = 4/12 - 1/2
2/a = 3/12
1/a = 3/24
a = 24/3 = 8 hr
