For these questions you will you the same techniques as the worked example for direct proportions.  You might also have to use some other skills you have learnt about the slide rule.  Read and check each question carefully.  When you are ready you can check your answers by clicking on the link below the questions.

Question 1:

5 m of curtain material cost $115.  Find the cost of:

(a) 1 m;
(b) 9 m.

 Question 2:

8 kg of potatoes cost $4.72.  Find the cost of:

(a) 1 kg;
(b) 20 kg.

 Question 3:

A car travels 270 km on 30 L of petrol.  How far does it travel on 20 L?

 Question 4:

A tree 5 m high casts a shadow 10 m long.  At the same time another tree casts a shadow of 15 m long.  How high is this tree?

 Question 5:

In factory tests it was found that for every 10000 light globes produced, 15 were faulty.  How many are faulty if 8000 are tested?

 Question 6:

If 2.5 m of material can be bought for $10, how many meters should you be able to buy for $26.

Check your answers here!