Thread: Please help me with this question!

Please help!

A service station has 2 kinds of oil, one selling for $1.27/litre and the other for $1.18/litre. How many litres of each must be used to make 90 litres of a mixture that can be sold for $1.24/litre?

Originally Posted by princess_anna57

Please help!

A service station has 2 kinds of oil, one selling for $1.27/litre and the other for $1.18/litre. How many litres of each must be used to make 90 litres of a mixture that can be sold for $1.24/litre?

Let x be the number of litres of the 1.27 oil, then there are 90-x litres of
the other. The price of the mixture will be:

(1.27*x+1.18*(90-x))/90 dollars per litre.

You will need to find x such that the price of the mixture will be 1.24.

RonL

Originally Posted by princess_anna57

Please help!

A service station has 2 kinds of oil, one selling for $1.27/litre and the other for $1.18/litre. How many litres of each must be used to make 90 litres of a mixture that can be sold for $1.24/litre?

Hello,

let x be the amount of oil which is sold for $1.27
then (90-x) is the amount of oil which is sold for $1.18.

Now you can set up the equation:

. Expand the bracket and collect like terms :



. Divide both sides of the equation by 0.09 and you'll get:



That means: Take 60 ltrs of the $1.27-oil and 30 ltrs of the $1.18-oil to get the mixture which you can sell for $1.24