PSLE The airmail rates to two countries are shown. Zoe sent a letter weighing 85g to Vietnam and a letter weighing 24g to Switzerland by airmail. How much did she pay altogether?
Mass |
Vietnam |
Switzerland |
First 30g |
$0.85 |
$1.80 |
Every additional 15g |
$0.55 |
$0.80 |
Mass of the letter to Vietnam excluding the first 30 g
= 85 - 30
= 55 g
Sets of additional 15 g of the letter to Vietnam
= 55 ÷ 15
= 3 r 10
Sets of additional 15 g and part thereof the letter to Vietnam
= 3 + 1
= 4
Amount that Zoe paid for the letter to Vietnam
= 0.85 + 4 x 0.55
= 0.85 + 2.20
= $3.05
Amount that Zoe paid altogether
= 3.05 + 1.80
= $4.85
Answer(s): $4.85