GCSE Secondary Maths Age 13-17 - Ratio, Proportion & Rates of Change: Percentages - Explained

The video tutorial explains how to solve a reverse percentage problem using a bread weight example. It starts by introducing the concept of reverse percentages and then presents a problem where a loaf of bread loses 12% of its weight during baking. The goal is to find the original weight of the bread before baking. The tutorial walks through the calculation steps, verifies the solution, and discusses the marking scheme. It concludes with tips on identifying reverse percentage problems.

What percentage of its original weight does the bread retain after baking?

• 12%

• 88%

• 100%

• 1.1%

If the baked loaf weighs 1.1 kg, what is the formula to find the original weight of the bread?

• 1.1 - 12

• 1.1 * 88 / 100

• 1.1 + 12

• 1.1 / 88 * 100

What is the original weight of the bread before baking if the baked weight is 1.1 kg?

• 0.88 kg

• 1.25 kg

• 1.12 kg

• 1.1 kg

How many marks are awarded for identifying the problem as a reverse percentage question?

• Three marks

• One mark

• Two marks

• No marks

Why is it important to read the question carefully in percentage problems?

• To calculate faster

• To avoid using a calculator

• To memorize the question

• To identify the type of percentage problem