The table shows the airmail rates for sending letters and postcards to some countries.
Destination |
Letters |
Postcards |
|
Mass |
Postage Rate |
Per piece |
New Zealand, Australia
|
1st 20 g |
$1.10 |
$0.90
|
Every additional 10 g or part thereof |
$0.35 |
How much did Cathy pay for the postage when she sent a letter which weighed 53 g and 4 postcards to Australia by airmail?
Remaining mass that Cathy had to pay for the letter as it was more than 20 g
= 53 - 20
= 33 g
Number of sets of additional 10 g of the letter that Cathy had to pay for
= 33 ÷ 10
= 3 r 3
Total number of sets of additional 10 g of the letter that Cathy had to pay for
= 3 + 1
= 4
Amount that Cathy had to pay for the sets of additional 10 g of the letter
= 4 x 0.35
= $1.40
Total amount that Cathy had to pay for the letter
= 1.10 + 1.40
= $2.50
Amount that Cathy had to pay for the 4 postcards
= 4 x 0.90
= $3.60
Total amount that Cathy paid
= 2.50 + 3.60
= $6.10
Answer(s): $6.10