Question

petrol and engine oil has to mix in the ratio 5 : 2 for a certain motorcycle how much engine oil is needed to mix with 10 litres of petrol ​

Answer 1

Explanation:

Set this up as a ratio of proportions of petrol : oil

`(p)/(o)` and if the ratio of the mix has to be 5p to 2 oil then:

`(p)/(o):(5)/(2)` We need to find how much oil, x, is needed to mix with 10 liters of petrol. Completing the proportion with that ratio gives us the problem in its entirety:

`(p)/(o):(5)/(2)=(10)/(x)` and cross multiply

5x = 20 so

x = 4 liters of oil are needed to mix with 10 liters of petrol.