Introduction to Proportion and Best Buys

The video tutorial explains the concepts of direct and inverse proportion, providing real-life examples for each. Direct proportion is when two values increase at the same rate, while inverse proportion is when one value increases as the other decreases. The unitary method is used to solve problems related to these concepts. The tutorial also covers how to find the best value for money using the unitary method and comparison techniques.

Which of the following is an example of direct proportion?

• The faster you drive, the less time it takes to reach your destination.

• The more units you buy in bulk, the less it costs per unit.

• The more jars of coffee you buy, the more it costs.

• The more workers you have, the less time it takes to build a wall.

If three coffees cost £7.50, how much would five coffees cost using the unitary method?

• £15.00

• £12.50

• £10.00

• £17.50

In an inverse proportion, what happens when one value increases?

• The other value increases at the same rate.

• The other value doubles.

• The other value decreases at the same rate.

• The other value remains constant.

If it takes three men four days to build a wall, how long would it take two men?

• 16 days

• 8 days

• 6 days

• 12 days

What is the first step in determining the best buy using the unitary method?

• Finding the cost per unit.

• Finding the total cost of all items.

• Calculating the average cost.

• Comparing the total quantities.

Which method involves finding equal quantities to compare values?

• Unitary method

• Lowest common multiple method

• Inverse proportion method

• Direct proportion method

If Doughs 'R' Us offers 3 doughnuts for £1.05, what is the cost per doughnut?

• 38p

• 37p

• 36p

• 35p