PSLE The airmail rates to two countries are shown. Gabby sent a letter weighing 77g to Indonesia and a letter weighing 12g to New Zealand by airmail. How much did she pay altogether?
Mass |
Indonesia |
New Zealand |
First 20g |
$0.75 |
$1.50 |
Every additional 10g |
$0.55 |
$0.55 |
Mass of the letter to Indonesia excluding the first 20 g
= 77 - 20
= 57 g
Sets of additional 10 g of the letter to Indonesia
= 57 ÷ 10
= 5 r 7
Sets of additional 10 g and part thereof the letter to Indonesia
= 5 + 1
= 6
Amount that Gabby paid for the letter to Indonesia
= 0.75 + 6 x 0.55
= 0.75 + 3.30
= $4.05
Amount that Gabby paid altogether
= 4.05 + 1.50
= $5.55
Answer(s): $5.55