hi. I am new to this. A lot of my friends recommended me to come here. I have two questions that I need help with. Can you please explain how to do this.

Question

1) I pay £56.25 for 15 bags of gravel. How much would 7 bags cost?

2) An aeroplane travels 320km in 20 minutes. How far will it travel in three minutes?

Answer 1

In both questions, your method should first be to find the cost/distance for one bag/one minute, and then multiply for the given amount.

a) If you pay 56.25 for 15 bags, then you pay (56.25/15) for 1.
If you pay (56.25/15) for 1 bag, then you pay (56.25/15)*7 for seven.

Hence, 7 bags would cost:
(56.25/15)*7
= 3.75*7
= £25.97

b) If the aeroplane travels 320km in 20 minutes, then it travels (320/20)km in one minute.
Then, it travels (320/20)*3 km in three minutes.
= (320/20)*3
= 12*3
= 48km

Answer 2

thanks I understand now.