Question

A candy store merchant sells 25 kg of ju-jubes for $3.00/kg. If he uses one brand selling for $2.25/kg and a second brand selling at $3.75/kg, how much of each brand is required?

Answer 1

`12.5` kg of each brand is required.

Explanation:

Method 1)
Average of selling prices of brand `1 ($2.25)` and brand `2 ($3.75)` is `(3.75+2.25)/2 = $3.0` which is also original one `$3`.
So `25/12=12.5` kg of each brand is required.

Method 2)

Let quantity of brand 1 required is `x` kg and quantity of brand 2 required is `y` kg.

So `x+y =25 or x=25-y` (1) and `x*2.25+y*3.75 = (25*3) or 2.25x + 3.75 y =75` (2) or `2.25(25-y) +3.75 y =75`
or `56.25 - 2.25y +3.75y =75` or
`1.5y=75-56.25 =18.75 or y= 18.75/1.5 = 12.5` kg `:. x=25-y=25-12.5=12.5` kg.

So `12.5` kg of each brand is required. [Ans]