2.2.1 Try some yourself
Activity 12
A recipe for four people calls for 
teaspoon of mustard powder. How much should you use for ten people?
Answer
For one person you need 
teaspoons.
For ten people you need 
teaspoons.
So almost 2 teaspoons of mustard are needed.
Activity 13
The length of time it takes to cook a Christmas pudding in a pressure cooker depends on the weight of the pudding. Kim has forgotten the time per pound but remembers that her 
kg pudding takes 5 hours.
How long will it take to cook a 2 kg pudding?
Answer
If it takes 5 hours to cook 
kg then the time to cook 1 kg is 5 ÷ hours.
So a 2 kg pudding takes 
hours (6 hours 40 mins), assuming that cooking time is proportional to weight.