Question

A motorbike uses petrol and oil mixed in the ratio 13:2

a)how much of each is there in 30 litres of mixture ?
b) how much petrol would be mixed with 500 ml of oil?

Answer 1

Part A)
`26\ liters` of petrol and
`4\ liters` of oil

part B)
`3.25\ liters` or
`3,250\ ml` of petrol

Explanation:

Part A) How much of each is there in 30 liters of mixture ?

Let

x-----> the amount of liters of petrol

y----> the amount of liters of oil

we know that

`(x)/(y)=(13)/(2)`

`x=(13)/(2)y` -----> equation A

`x+y=30` ---> equation B

substitute equation A in equation B

`(13)/(2)y+y=30`

`(15)/(2)y=30`

`y=30*2/15=4\ liters`

Find the value of x

`x=(13)/(2)(4)=26\ liters`

Part B) How much petrol would be mixed with 500 ml of oil?

Convert ml to l

`500\ ml=0.50\ l`

we know that

using proportion

`(13)/(2)=(x)/(0.5)\\ \\x=13*0.5/2\\ \\x=3.25\ l`