Peter currently earns $21.50 per hour - HSC - SSCE Mathematics Standard - Question 5 - 2021 - Paper 1

To determine Peter's hourly wage after four years, we can use the formula for compound interest, which is:

$A = P(1 + r)^n$

where:

• $A$ is the amount of money accumulated after n years, including interest.
• $P$ is the principal amount (the initial amount of money).
• $r$ is the annual interest rate (decimal).
• $n$ is the number of years the money is invested for.

Here, Peter's initial wage ($P$) is $21.50, the annual interest rate ($r$) is 2.1$n$) is 4 years. Substituting these values into the formula gives:

$A = 21.50(1 + 0.021)^4$

Calculating this, we find:

• First, evaluate $1 + 0.021 = 1.021$.
• Then raise it to the power of 4: $1.021^4$.
• Finally, multiply by $21.50$ to find the hourly wage after four years.

Thus, the correct option from the given choices is B: $21.50(1.021)^4$.