Question

Thaddeus shakes his head as he pays $12.37 to the clerk for lunch. Complaining to a friend, Thaddeus says, "Do you realize that is 0.2% of my monthly income?" His friend replies, "I think you made a mistake. That should be 2%. You messed up on the decimal point." (a) Assuming Thaddeus is not wrong, what is his monthly income? (b) If Thaddeus' friend is correct, what is Thaddeus' monthly income?​

Answer 1

a) If Thaddeus is not wrong, his monthly income is $6,185.

x/12.37 = 100/0.2

0.2x = 1237

x = 1237/0.2x

x = 6,185

b) If Thaddeus's friend is correct, Thaddeus's monthly income is $618.5

x/12.37 = 100/2

2x = 1237

x = 1237/2x

x = 618.5

Answer 2

Ronisha invests $5000 in an account that earns 2.3% annual simple interest. After 3 years, Ronisha invests the interest earned in a second account. This account earns 3.2% annual interest. Ronisha leaves the money in this account until she has earned $55.20 in interest.