Answer:
Part A: The total cost of 10 stamps = $3.4
Part B: The total cost of 100 stamps = $34
Explanation:
The cost of each postcard stamp = $0.34
Part A:
Number of postcard Natalie buys = 10
So, the cost of 10 postcard stamps = 10 x Cost of each stamp
= 10 x ($0.34) = $3.4
or, the total cost of 10 stamps = $3.4
Part B:
Number of postcard Natalie buys = 100
So, the cost of 100 postcard stamps = 100 x Cost of each stamp
= 100 x ($0.34) = $34
or, the total cost of 100 stamps = $34