}
problem:
You can buy 4 bananas at the supermarket A for $ 1.08.
You can buy 5 of the same bananas at the supermarket B for $ 1.24
Which place is the better buy?
answer:
1. step: proportion
supermarket A supermarket B
: 4 bananas – 1.08$ : 5 bananas – 1.24 $
* 1 banana – x $ * 1 banana – x $
2. step: which proportion?
↓less bananas ↓less $ = direct proportion for both
3. step: formula
supermarket A supermarket B
x = 1.08 : 4 * 1 x = 1.24 : 5 * 1
x = 0.27 $ x = 0.25 $
4. step: answer
Supermarket B is the better buy.