You wash dishes for a chemistry laboratory to make extra money for laundry. you earn 12 dollars/hour, and each shift lasts 75 minutes. your laundry requires 12 quarters/load. a. how many shifts must you work if you wish to wash 10 loads of laundry? b. how many loads of laundry can you wash if you work 3 shifts? c. how many loads of laundry will each shift pay for if the cost per load rises to 16 quarters?

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