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

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

correct answer is infinitely many solutions

step-by-step explanation:

2(2x + 3) = -4 + 2(2x + 5)

solving the above equation:

4x + 6 = -4 +4x +10

combining like terms

4x -4x = -4+10-6

0=0

since both sides are 0=0, we end up into true statement it means it has infinite many solutions.

so correct answer is infinitely many solutions