The table shows the airmail rates for sending letters and postcards to some countries.

Destination	Letters		Postcards
	Mass	Postage Rate	Per piece
Korea, Japan	1st 30 g	$1.70	$0.90
	Every additional 10 g or part thereof	$0.35

How much did Fanny pay for the postage when she sent a letter which weighed 55 g and 6 postcards to Korea by airmail?
Remaining mass that Fanny had to pay for the letter as it was more than 30 g
= 55 - 30
= 25 g

Number of sets of additional 10 g of the letter that Fanny had to pay for 
= 25 ÷ 10
= 2 r 5

Total number of sets of additional 10 g of the letter that Fanny had to pay for 
= 2 + 1
= 3

Amount that Fanny had to pay for the sets of additional 10 g of the letter
= 3 x 0.35
= $1.05

Total amount that Fanny had to pay for the letter
= 1.70 + 1.05
= $2.75

Amount that Fanny had to pay for the 6 postcards
= 6 x 0.90
= $5.40

Total amount that Fanny paid
= 2.75 + 5.40
= $8.15

Answer(s): $8.15