Q4: a recipe calls for 3 cups of cornstarch. one cup of cornstarch weighs 4.5 ounces. how
much would 1 cup cost if the price of cornstarch was $0.98 per pound?

ANSWER:  

One cup of cornstarch weighs 4.5 ounces.The cost of 1 cup is $0.286 approximately.

SOLUTION:

Given, One cup of cornstarch weighs 4.5 ounces.  

The price of cornstarch was $0.98 per pound.

We need to find 1 cup cost.

Cost of a cup is product of cornstarch weight in cup and price of cornstarch per pound.

1 cup cost = cornstarch weight price of cornstarch per pound.

Here, both the terms are in different units, we need to convert them into single unit.

Let us convert ounces into pounds

We know that, 1 pound = 16 ounces

1 ounce = pound

Now, one cup of cornstarch weighs 4.5 ounces

Then, cup of cornstarch weight in pounds =

=

= 0.28125 pounds

Now, cost of 1 cup = cornstarch weight x price of cornstarch per pound

= 0.28125 x 0.98

= 0.275625

Hence, the cost of 1 cup is $0.286 approximately