PSLE The airmail rates to two countries are shown. Erika sent a letter weighing 85g to Indonesia and a letter weighing 39g to Sweden by airmail. How much did she pay altogether?
Mass |
Indonesia |
Sweden |
First 40g |
$0.55 |
$1.80 |
Every additional 20g |
$0.25 |
$0.80 |
Mass of the letter to Indonesia excluding the first 40 g
= 85 - 40
= 45 g
Sets of additional 20 g of the letter to Indonesia
= 45 ÷ 20
= 2 r 5
Sets of additional 20 g and part thereof the letter to Indonesia
= 2 + 1
= 3
Amount that Erika paid for the letter to Indonesia
= 0.55 + 3 x 0.25
= 0.55 + 0.75
= $1.30
Amount that Erika paid altogether
= 1.30 + 1.80
= $3.10
Answer(s): $3.10