Question

A student can type a 32-page term paper in three hours. The student's

friend could type the paper in two hours. If they work together how long
would it take the two of them to type the paper?

Answer 1

1.2 hours, or 1 hour 12 minutes.

Explanation:

The first student's speed is 1 paper / 3 hours.

The second student's speed is 1 paper / 2 hours.

Their combined speed is:

1/3 + 1/2

= 2/6 + 3/6

= 5/6 paper/hour

So the time it takes to complete one paper is:

1 paper = 5/6 paper/hour × t

t = 6/5 hours

t = 1.2 hours, or 1 hour 12 minutes.