Answer:
I have just wrote answers
140 quarts of oil
49 quarts÷7 cars=7 quarts per car
7 quarts×20 cars=140 quarts
Please make it a little more understandable
Step 1
Given;

Required; To find the difference in interest between the two periods.
Step 2
State the formula for simple interest

Step 3
Find the interest when the rate is 8%

Therefore the interest is given as;

Step 4
Find the interest in 1980 with a 20% rate

The interest is given as;

Step 5
Find the difference in interest between the two rates.

Hence, the difference in interest between the two rates = $11095.89
Answer:
aWht is this .??????????????