PSLE The airmail rates to two countries are shown. Sarah sent a letter weighing 93g to Laos and a letter weighing 38g to China by airmail. How much did she pay altogether?
Mass |
Laos |
China |
First 40g |
$0.65 |
$1.40 |
Every additional 20g |
$0.35 |
$0.40 |
Mass of the letter to Laos excluding the first 40 g
= 93 - 40
= 53 g
Sets of additional 20 g of the letter to Laos
= 53 ÷ 20
= 2 r 13
Sets of additional 20 g and part thereof the letter to Laos
= 2 + 1
= 3
Amount that Sarah paid for the letter to Laos
= 0.65 + 3 x 0.35
= 0.65 + 1.05
= $1.70
Amount that Sarah paid altogether
= 1.70 + 1.40
= $3.10
Answer(s): $3.10