Answer:
A)You must work 2 shifts to wash 10 loads of laundry
B)You can wash 15 loads pf laundry if you work for 3 shifts
C) each shift will pay for 3.75 loads of laundry if the cost per load rises to 16 quarters
Explanation:
Given:
amount earned = 12 dollars/hour
Duration for one shift = 75 minutes
Amount needed for Laundry = 12 quarters/load.
A. How many shifts must you work if you wish to wash 10 loads of laundry
To wash 10 loads, you will be requiring
=> 
=> 120 quarters
1 quarter = 0.25 dollars---------------------------------(1)
120 quarters
= 
= 30 dollars
You need 30 dollars for washing 10 loads
In one hour i,e 60 minutes you earn= 12 dollars
In one minute the amount earned will be
= 0.2 dollar-------------------------------------------------------(2)
Now to earn 30 dollars you have to work for
=
minutes
= 150 minutes
Thus the number of shifts will be
= 
= 2 shifts
B. How many loads of laundry can you wash if you work 3 shifts
We Know that 1 shift = 75 minutes
So 3 shifts = 
= 225 minutes
From (2),
In 1 minute = 0.2 dollars is earned
So in 225 minutes = 225 \ times 0.2 = 45 dollar is earned
45 dollar = 
= 180 quarters
You can wash 1 load with 12 quarters
With 180 quarters you can wash = 
= 15 loads
C. How many loads of laundry will each shift pay for if the cost per load rises to 16 quarters
Cost per load = 16 quarters
From (1)
16 quarters = 
= 4 dollars per load
From (2) In 1 shift the amount earned will be
=> 
=15 dollars
With 4 dollars you can wash 1 load
So with 15 dollars = 
= 3.75 loads
