Question

Machine A takes a hours to make 100 bolts, and machine B takes b hours to make 100 bolts. How many

bolts will the two machines, working together, make in one hour?

Answer 1

100(1/a + 1/b)

Explanation:

Machine A takes a hours to make 100 bolts

• Then machine A makes 100/a bolts in one hour

Machine B takes b hours to make 100 bolts

• Then machine B makes 100/b bolts in one hour

Two machines will make:

• 100/a + 100/b = 100(1/a + 1/b)

bolts in one hour