PSLE The airmail rates to two countries are shown. Tiffany sent a letter weighing 77g to Indonesia and a letter weighing 30g to New Zealand by airmail. How much did she pay altogether?
Mass |
Indonesia |
New Zealand |
First 40g |
$0.75 |
$1.70 |
Every additional 20g |
$0.35 |
$0.75 |
Mass of the letter to Indonesia excluding the first 40 g
= 77 - 40
= 37 g
Sets of additional 20 g of the letter to Indonesia
= 37 ÷ 20
= 1 r 17
Sets of additional 20 g and part thereof the letter to Indonesia
= 1 + 1
= 2
Amount that Tiffany paid for the letter to Indonesia
= 0.75 + 2 x 0.35
= 0.75 + 0.70
= $1.45
Amount that Tiffany paid altogether
= 1.45 + 1.70
= $3.15
Answer(s): $3.15