Question

Janet collects stamps and wants to make a collage by placing them next to each other neatly in a 2 1/2 ft by 1 ft poster board. If the stamps are 2 in squares and the poster is completely covered, how many stamps are on the poster?

A) 15
B) 90
C) 120
D) 150

Answer 1

To find the number of stamps on the poster, we need to calculate the total area of the poster board and then divide it by the area of each stamp.

Given:

Poster board dimensions: 2 1/2 ft by 1 ft

Stamp size: 2 in by 2 in

First, we need to convert the measurements to a common unit. Let's convert everything to inches since the stamp size is given in inches.

1 ft = 12 inches (since 1 foot = 12 inches)

2 1/2 ft = 2 ft + 1/2 ft = 24 inches + 6 inches = 30 inches

Now, we can calculate the area of the poster board:

Area of poster board = Length × Width = 30 inches × 12 inches = 360 square inches

Next, we find the area of each stamp:

Area of each stamp = Length × Width = 2 inches × 2 inches = 4 square inches

Now, we can find the number of stamps on the poster by dividing the total area of the poster board by the area of each stamp:

Number of stamps = Total area of poster board ÷ Area of each stamp = 360 square inches ÷ 4 square inches = 90 stamps

Therefore, there are 90 stamps on the poster.

The correct answer is:

B) 90