Question

5. Friday morning the Matthews family goes to town to buy groceries. The following three

options are available for cereal:
CEREAL
CEREAL
CEREAL
Option 1:
300 g for $3.89
Option 2:
450 g for $4.77
Option 3:
600 g for $6.59
Which option is the best buy? Justify your answer. (17)

Answer 1

Explanation:

Hello!

To compare different prices of several brands of a product the best is to express the price for the same quantities of product.

Since the three options are original in 300g, 450g and 600g, I'll express all prices on a base of 100g of product. You can use simple rule of three for this:

Option 1

300g cost $3.89

100g cost
`(100*3.89)/(300) = $1.296`

Option 2

450g cost $ 4.77

100g cost
`(100*4.77)/(450)= $1.06`

Option 3

600g cost $ 6.59

100g cost
`(100*6.59)/(600)= 1.098`

So:

Option 1: $1.296/ 100g

Option 2: $1.06/100g

Option 3: $1.098/100g

The cheapest option is number 2

I hope this helps!