PSLE The airmail rates to two countries are shown. Dana sent a letter weighing 72g to Laos and a letter weighing 20g to Switzerland by airmail. How much did she pay altogether?
Mass |
Laos |
Switzerland |
First 30g |
$0.75 |
$1.10 |
Every additional 15g |
$0.55 |
$0.45 |
Mass of the letter to Laos excluding the first 30 g
= 72 - 30
= 42 g
Sets of additional 15 g of the letter to Laos
= 42 ÷ 15
= 2 r 12
Sets of additional 15 g and part thereof the letter to Laos
= 2 + 1
= 3
Amount that Dana paid for the letter to Laos
= 0.75 + 3 x 0.55
= 0.75 + 1.65
= $2.40
Amount that Dana paid altogether
= 2.40 + 1.10
= $3.50
Answer(s): $3.50