PSLE The airmail rates to two countries are shown. Joelle sent a letter weighing 57g to Vietnam and a letter weighing 12g to Switzerland by airmail. How much did she pay altogether?
Mass |
Vietnam |
Switzerland |
First 20g |
$0.85 |
$1.30 |
Every additional 10g |
$0.45 |
$0.55 |
Mass of the letter to Vietnam excluding the first 20 g
= 57 - 20
= 37 g
Sets of additional 10 g of the letter to Vietnam
= 37 ÷ 10
= 3 r 7
Sets of additional 10 g and part thereof the letter to Vietnam
= 3 + 1
= 4
Amount that Joelle paid for the letter to Vietnam
= 0.85 + 4 x 0.45
= 0.85 + 1.80
= $2.65
Amount that Joelle paid altogether
= 2.65 + 1.30
= $3.95
Answer(s): $3.95