I can’t see the question.
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:
a. 10
b. 0.1
Step-by-step explanation:
a. The t-shirts comes in 5 sizes (Small,medium,large, extra large and extra extra large) and two colors orange and black. The total different type of shirts are 5*2=10 different type of t-shirts.Also if we make sample space of all shirts we can assess the total different type of t-shirts. sample space=S={small orange,medium orange,large orange,XL orange,XXL orange,small black,medium black,large black,XL black,XXL black}. n(S)=total different type of shirts=10.
b. P( large orange t-shirt)=n(large orange t-shirt)/n(S)=1/10=0.10.
R = 3(t+4) + 1
Hope it helps