Percentages (I) · Ages 12–13
Tax, pay and commission
Name the base first: a percentage of what?
How to do it
Method
Name the base first: a percentage of what?
380 × 10% = 38, 380 + 38 = 418
Another way
One multiplication
380 × 1.1 = 418
In full
Tax, a service charge, a pay rise and commission are all 'a percentage of some amount', so name the base first. A 10% service charge on a $380 bill: one way, the charge first, 380 × 10% = 38, 418 in all; another, in one step, 380 × 1.1 = 418. Tax = the taxable amount × the rate, so 15% of $60000 is $9000. A 5% pay rise: the new monthly pay = the old × 1.05. Commission = sales × the commission rate, and the month's pay = basic pay + commission. Where some steps take away and others add, check each step's base: the same rate on a different base is a different amount.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
Taxable amount $215,000, tax rate 10%: tax = $
Show the answer and working
Answer: 21,500
Tax = taxable amount × rate = 215000 × 10% = 21500.
Example 2
Sales of $171,000 at a 7% commission rate earn $1,197 in commission.
True or false?
Show the answer and working
Answer: False
7% is 7100: 171000 × 7100 = 11970.
Example 3
With 12% tax added, an item costs $873.6. What was its price before tax?
Show the answer and working
Answer: 780 dollars
The tax is of the price before tax: x × 1.12 = 873.6, so x = 873.6 ÷ 1.12 = 780.
Practice questions to try
Try these 5; the answers are at the end. For a whole worksheet, see VIP worksheets below.
1.Taxable amount $29,000, tax rate 16%: tax = $
Answer:
2.With 8% tax added, an item costs $1,350. What was its price before tax?
Answer:
3.Basic pay $11,500, plus 5% of sales as commission. With $40,000 of sales in a month, that month's pay = $
Answer:
4.A $1,830 bill: 10% off and then a 15% service charge, or the 15% charge first and then 10% off. Which costs less?
- A. They cost the same
- B. Adding the charge first
- C. Taking the discount first
- D. It depends on the bill
Choose the right answer
Answer:
5.A year's income of $275,000: after a $100,000 allowance, the rest is taxed at 14%. Tax = $
Answer:
All the answers
- 1. 4,640
- 2. 1,250 dollars
- 3. 13,500
- 4. A. They cost the same
- 5. 24,500
VIP practice notes and papers
Aimed at tests and exams: questions on this topic, new every time, to print or save as a PDF.
- Practice notes: The key point, worked examples step by step, then questions of the same kind to follow, hints fading
- Practice paper: Set out in parts like a school paper, marked, with answers and full working
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