PSLE The airmail rates to two countries are shown. Lucy sent a letter weighing 81g to Vietnam and a letter weighing 22g to India by airmail. How much did she pay altogether?
Mass |
Vietnam |
India |
First 30g |
$0.65 |
$1.70 |
Every additional 15g |
$0.35 |
$0.65 |
Mass of the letter to Vietnam excluding the first 30 g
= 81 - 30
= 51 g
Sets of additional 15 g of the letter to Vietnam
= 51 ÷ 15
= 3 r 6
Sets of additional 15 g and part thereof the letter to Vietnam
= 3 + 1
= 4
Amount that Lucy paid for the letter to Vietnam
= 0.65 + 4 x 0.35
= 0.65 + 1.40
= $2.05
Amount that Lucy paid altogether
= 2.05 + 1.70
= $3.75
Answer(s): $3.75