The table shows the airmail rates for sending letters and postcards to some countries.
Destination |
Letters |
Postcards |
|
Mass |
Postage Rate |
Per piece |
Thailand, Vietnam, Myanmar
|
1st 40 g |
$1.40 |
$0.90
|
Every additional 10 g or part thereof |
$0.40 |
How much did Opal pay for the postage when she sent a letter which weighed 106 g and 8 postcards to Thailand by airmail?
Remaining mass that Opal had to pay for the letter as it was more than 40 g
= 106 - 40
= 66 g
Number of sets of additional 10 g of the letter that Opal had to pay for
= 66 ÷ 10
= 6 r 6
Total number of sets of additional 10 g of the letter that Opal had to pay for
= 6 + 1
= 7
Amount that Opal had to pay for the sets of additional 10 g of the letter
= 7 x 0.40
= $2.80
Total amount that Opal had to pay for the letter
= 1.40 + 2.80
= $4.20
Amount that Opal had to pay for the 8 postcards
= 8 x 0.90
= $7.20
Total amount that Opal paid
= 4.20 + 7.20
= $11.40
Answer(s): $11.40