how much will $4,200 be worth in 5 years at 3% p.a. simple interest?

Explanation:

Step1: Recall simple interest formula

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

Step2: Convert rate to decimal

Given $r = 3% = 0.03$.

Step3: Calculate interest

Substitute $P = 4200$, $r = 0.03$, $t = 5$ into the interest formula: $I = 4200 \times 0.03 \times 5 = 4200 \times 0.15 = 630$.

Step4: Calculate total amount

Add principal and interest: $A = 4200 + 630 = 4830$? Wait, no, wait, 42000.03 is 126, 1265 is 630. 4200 + 630 = 4830? But wait, let me recalculate. Wait, 42003% is 42000.03 = 126 per year. For 5 years, 1265 = 630. Then total amount is 4200 + 630 = 4830? But wait, the options have $4,830 as one of them. Wait, but let me check again. Wait, maybe I made a mistake? Wait, 42000.035: 42005=21000, 21000*0.03=630. So 4200+630=4830. So the answer should be $4,830. Wait, but let me check the options. The first option is $4,830. So that's the answer. Wait, but wait, maybe I miscalculated? Wait, 3% of 4200 is 126, times 5 is 630. 4200+630=4830. Yes.

Answer:

$4,830$ (corresponding to the option with $4,830$)