Answer:
Mrs. Stern washed more
laundry still needs to be washed.
Step-by-step explanation:
Total amount of laundry: 
of the laundry still needs to be done.
Mrs. Stern washed 
of the laundry.
Her son washed 
of the laundry.
Mrs. Stern washed more laundry than her son.
<span>a) f(n) is the number of students in your calculus class whose birthday is on the nth day of the year.
f(n) is not invertible because several different days, n, may have the same number of students, f(n). Then for one specific f(n) you cannot determine a unique n.
b) f(x) is the volume in litters of x kilograms of water at 4 degrees celsius.?
f(x) is invertible because each x gives a different f(x), then you can determine unambiguously which f(x) corresponds to each x.
</span>
The ratio given says this - 3 puppies : 2 adults = 5 total dogs
You are given (?) puppies : (?) adults = 80 total dogs
In this case, you are trying to find the number of puppies, so you do not need to care about the number of adults. You need to compare the ratio with the actual amount.
Total/puppies = total/puppies
5/3 = 80/(?)
Now, cross multiply.
5(?) = 240
Divide both sides by 5 and you get your answer.
(?) = 48
