Video: AQA GCSE Mathematics Foundation Tier Pack 4 • Paper 2 • Question 31

In January 2013, the average price of petrol was £1.31 per litre; Lance used 125 litres of petrol. In January 2015, the average price of petrol was £1.08 per litre; Lance used 149 litres of petrol. Determine whether Lance spent more money on petrol in January 2013 or January 2015. You must show your working.

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Video Transcript

In January 2013, the average price of petrol was one pound 31 pence per litre; Lance used 125 litres of petrol. In January 2015, the average price of petrol was one pound eight pence per litre; Lance used 149 litres of petrol. Determine whether Lance spent more money on petrol in January 2013 or January 2015. You must show your working.

So to solve this problem, the first thing we need to do is work out how much money that Lance spent on petrol in January 2013 and January 2015. So we’ll start with January 2013. Well, we’re told that the average price of petrol was one pound 31 pence per litre. And we’re also told that Lance used 125 litres of petrol. So therefore, to work out how much money has been spent on petrol in each of these, so first of all January 2013, we’re gonna have to multiply the litres used by the cost per litre.

So therefore, what we’re gonna do is multiply 125, the litres used, by one pound 31 or 1.31, which is the cost per litre. It’s worth noting though that we’re only working out an estimate for the amounts of money that Lance spent on petrol. And this is because we’re told the average price of petrol. And it might not be in the exact price that he paid at each time he bought petrol. So when we multiply these two numbers together, we get 163 pounds and 75 pence. So we know that Lance spent 163 pounds and 75 pence on petrol in January 2013. And like I said, that’s our estimate.

So now to work out how much he spent in January 2015, what we’re gonna do is multiply 149 because that’s our litres used by 1.08 because that was the cost per litre which gives a total of 160 pounds and 92 pence. So that’s the estimate of how much Lance spent in January 2015.

Well, if we compare the two amounts of money, we can see that 163 pounds and 75 pence is greater than 160 pounds and 92 pence. So therefore, we can say that Lance spent more in January 2013 because in January 2013, he spent 163 pounds and 75 pence. And like we said, in January 2015, he spent 160 pounds and 92 pence.