PSLE The airmail rates to two countries are shown. Diana sent a letter weighing 78g to Laos and a letter weighing 25g to India by airmail. How much did she pay altogether?
Mass |
Laos |
India |
First 30g |
$0.75 |
$1.30 |
Every additional 15g |
$0.45 |
$0.35 |
Mass of the letter to Laos excluding the first 30 g
= 78 - 30
= 48 g
Sets of additional 15 g of the letter to Laos
= 48 ÷ 15
= 3 r 3
Sets of additional 15 g and part thereof the letter to Laos
= 3 + 1
= 4
Amount that Diana paid for the letter to Laos
= 0.75 + 4 x 0.45
= 0.75 + 1.80
= $2.55
Amount that Diana paid altogether
= 2.55 + 1.30
= $3.85
Answer(s): $3.85