How to answer it
- Break the problem into steps in the order they happen.
- Do each step with the result of the one before.
- Check the final answer is the quantity asked for.
Worked example
An original question in the ACT format, already answered.
ACT MathWorked example
A store takes 25% off a $40 shirt, then adds 8% sales tax to the sale price.
What does the shirt cost after tax?
- A$30.00
- B$32.40
- C$33.20
- D$37.80
Answer: B. The sale price is 40 × 0.75 = $30, and tax brings it to 30 × 1.08 = $32.40. Choice C combines the percents as 40 × (1 − 0.25 + 0.08), which is wrong.
The most common trap
Adding and subtracting percents directly. Apply each one to the right base, in order.
Practice it
Hourly Prep’s daily sets mix integrating essential skills with the rest of ACT Math, and send more of it your way when it’s a weak spot. See how the ACT prep plan works, or browse the other ACT skill guides.