Question

1. _____ how much interest does a $407 investment earn at 6% over seven years?
2. _____ if you borrow $491 for one year at an interest rate of 3%, how much interest will you pay?
3. _____ how much interest is earned on a principal of $646 invested at an interest rate of 5% for two years?
4. _____ how much interest is earned on $470 at 4% for seven years?

Explanation:

Question 7

Step1: Recall simple interest formula

The simple interest formula is $I = P \times r \times t$, where $I$ is the interest, $P$ is the principal amount, $r$ is the annual interest rate (in decimal), and $t$ is the time in years.

Step2: Convert rate to decimal

The interest rate is 6%, so $r = 0.06$. The principal $P = 407$ and time $t = 7$.

Step3: Calculate interest

Substitute the values into the formula: $I = 407 \times 0.06 \times 7$. First, calculate $407 \times 0.06 = 24.42$. Then, $24.42 \times 7 = 170.94$.

Step1: Recall simple interest formula

Use $I = P \times r \times t$.

Step2: Convert rate to decimal

Rate is 3%, so $r = 0.03$. Principal $P = 491$, time $t = 1$.

Step3: Calculate interest

Substitute: $I = 491 \times 0.03 \times 1 = 14.73$.

Step1: Recall simple interest formula

$I = P \times r \times t$.

Step2: Convert rate to decimal

Rate is 5%, so $r = 0.05$. Principal $P = 646$, time $t = 2$.

Step3: Calculate interest

Substitute: $I = 646 \times 0.05 \times 2$. First, $646 \times 0.05 = 32.3$. Then, $32.3 \times 2 = 64.6$.

Answer:

The interest earned is $\$170.94$.

Question 8