Question

Working together, Katherine and Marina can sand a large cabinet in 2 hours. It would take Katherine 10 hours to do the job alone.

What is the value of r, the part of the job that Marina can complete in 1 hour?

0.1
0.4
0.5
0.6

Answer 1

b

Explanation:

Answer 2

Option 2

The part of the job that Marina can complete in 1 hour

Explanation

Working together, Katherine and Marina can sand a large cabinet in 2 hours.

In hour the complete 1/2 of total work

It would take Katherine 10 hours to do the job alone.

In one hour Katherine complete 1/10 of total work

Let r, the part of the job that Marina can complete in 1 hour

So we can write,

r = 1/2 -1/10 = 0.4

The part of the job that Marina can complete in 1 hour is 0.4