PSLE The airmail rates to two countries are shown. Gem sent a letter weighing 55g to Laos and a letter weighing 19g to Switzerland by airmail. How much did she pay altogether?
Mass |
Laos |
Switzerland |
First 20g |
$0.95 |
$1.80 |
Every additional 10g |
$0.65 |
$0.80 |
Mass of the letter to Laos excluding the first 20 g
= 55 - 20
= 35 g
Sets of additional 10 g of the letter to Laos
= 35 ÷ 10
= 3 r 5
Sets of additional 10 g and part thereof the letter to Laos
= 3 + 1
= 4
Amount that Gem paid for the letter to Laos
= 0.95 + 4 x 0.65
= 0.95 + 2.60
= $3.55
Amount that Gem paid altogether
= 3.55 + 1.80
= $5.35
Answer(s): $5.35