Question

In a '20% off' sale, a coat was £220. Work out the original price.

Answer 1

80% is equal to 220

1) Set up a proportion:
80/100=220/x

2) Simplify:
4/5=220/x

3) Solve by cross-multiplying:
4x=1100
x=275

Original Price: 275

Answer 2

80% of p = 220 (We know this as the sale price is 20% off, so there is still 80%)

0.8p = 220

p = 220/0.8 (This is because we are making p the subject of the formula)

p = 275 (If you are not allowed to use a calculator for this, then: 220/0.8 is the same as 2200/8 because we are just simply multiplying both the numerator and denominator by 10. This can be simply worked out by long division)