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2. Alex invests [tex]\$200[/tex] for 2 years at a rate of [tex]2\%[/tex] per year simple interest. Chris invests [tex]\$200[/tex] for 2 years at a rate of [tex]2\%[/tex] per year compound interest. Calculate how much more interest Chris has than Alex.

Sagot :

Sure, let's solve this step-by-step.

### Step 1: Understanding Simple Interest

Formula for Simple Interest:
[tex]\[ \text{Simple Interest} = P \times r \times t \][/tex]

Where:
- [tex]\( P \)[/tex] is the principal amount: [tex]$200 - \( r \) is the annual interest rate: 2% or 0.02 - \( t \) is the time in years: 2 Let's plug in the values: \[ \text{Simple Interest} = 200 \times 0.02 \times 2 \] \[ \text{Simple Interest} = 200 \times 0.04 = 8 \] So, Alex earns $[/tex]\[tex]$8$[/tex] in simple interest.

### Step 2: Understanding Compound Interest

Formula for Compound Interest:
[tex]\[ A = P \times (1 + r)^t \][/tex]

Where:
- [tex]\( A \)[/tex] is the amount of money accumulated after n years, including interest.
- [tex]\( P \)[/tex] is the principal amount: [tex]$200 - \( r \) is the annual interest rate: 2% or 0.02 - \( t \) is the time the money is invested for in years: 2 We need to calculate the total amount accumulated (A) and then find the compound interest by subtracting the principal from this amount. Let's plug in the values: \[ A = 200 \times (1 + 0.02)^2 \] \[ A = 200 \times (1.02)^2 \] \[ A = 200 \times 1.0404 \] \[ A = 208.08 \] Compound Interest: \[ \text{Compound Interest} = A - P \] \[ \text{Compound Interest} = 208.08 - 200 \] \[ \text{Compound Interest} = 8.08 \] So, Chris earns approximately $[/tex]\[tex]$8.08$[/tex] in compound interest.

### Step 3: Calculating the Difference

To determine how much more interest Chris earns compared to Alex, we subtract the simple interest earned by Alex from the compound interest earned by Chris:
[tex]\[ \text{Difference in Interest} = \text{Compound Interest} - \text{Simple Interest} \][/tex]

[tex]\[ \text{Difference in Interest} = 8.08 - 8.00 \][/tex]

[tex]\[ \text{Difference in Interest} = 0.08 \][/tex]

So, Chris earns [tex]$\$[/tex]0.08$ more in interest than Alex over the 2-year period.