500g of an item costs $12. Use the unitary method to find the equivalent cost of 320g.
a Find the cost of 100g for each price.
b Which size can is sold at a cheaper rate?

Respuesta :

a) 500g=$12 -> 100g=12:5 100g=$2,40
20g=2,40:5=$0,58
320g=3x2,40+0,58
320g=7,20+0,58
320g=7,78$