PSLE The airmail rates to two countries are shown. Lucy sent a letter weighing 92g to Vietnam and a letter weighing 33g to Switzerland by airmail. How much did she pay altogether?
Mass |
Vietnam |
Switzerland |
First 40g |
$0.55 |
$1.60 |
Every additional 20g |
$0.25 |
$0.50 |
Mass of the letter to Vietnam excluding the first 40 g
= 92 - 40
= 52 g
Sets of additional 20 g of the letter to Vietnam
= 52 ÷ 20
= 2 r 12
Sets of additional 20 g and part thereof the letter to Vietnam
= 2 + 1
= 3
Amount that Lucy paid for the letter to Vietnam
= 0.55 + 3 x 0.25
= 0.55 + 0.75
= $1.30
Amount that Lucy paid altogether
= 1.30 + 1.60
= $2.90
Answer(s): $2.90