Answer: 3.75 per shift
Step-by-step explanation:
Given : The amount earned by laundry = 12 dollars / hour
Since 1 dollar = 4 quarters.
Then, amount earned per hour=
quarters per hour.
[By unitary method]
The time period for each shift = 75 minutes
Since 1 hour = 60 minutes
Then , 1 minute =
hours [By unitary method]
Now, 75 minutes =
hours
Now, the total amount earned from each shift will be:-
quarters
Now , the cost of laundry= 12 quarters/load
The cost of load after increment = 16 quarters
Then, the number of loads can be washed :-

Hence, number of loads of laundry = 3.75 per shift