[The narrator reads out the onscreen text.]

NARRATOR: Question four. David bought a pair of shoes at a discounted price of $80. If the discount was 25%, what was the original price? Method one. If the discount was 25%, that means that the $80 discounted price was 75% of the original price. So 75% of the original price is $80. This allows us to work out what 25% is since 25% is one-third of 75%. So 25% of the original price is 80 divided by 3. Which then means that 100% of the original price, which is 4 times 25%, is equivalent to 80 divided by 3 and multiplied by 4. So we get 320 divided by 3 which is 106 and two-thirds, so 106.6 recurring. So this means that the original price was $106.67 correct to the nearest cent. Method two. If the discount was 25%, that means that the $80 discounted price was 75% of the original price. So 75% of the original price is equal to $80. 75% is the same as 75 over 100. Multiplied by the original price - which is the unknown in this situation, so I'm going to call it x - is equal to $80. 75 over 100 simplifies to three-quarters, multiplied by x equals 80. So x is going to be equal to 80 divided by three-quarters, which is 80 multiplied by four-thirds, which is 320 divided by 3, which, as we worked out earlier, gives $106.67 correct to the nearest cent.