Q: Libby is building an igloo in her backyard using bricks of snow. She builds her igloo in rows, using a total of 10 rows of bricks of snow. The bottom half of the igloo has 12 bricks of snow in each row while the top half of the igloo has 8 bricks of snow in each row. How many bricks of snow did Libby use for her igloo?
A: 100
Explain how we arrive at this answer:
Explanation: In the bottom half of the igloo, there are 10 rows / 2 = 5 rows of bricks of snow. So in the bottom half of the igloo, there are 5 rows * 12 bricks of snow in each row = 60 bricks of snow. In the top half of the igloo, there are 5 rows * 8 bricks of snow in each row = 40 bricks of snow. There is therefore a total of 60 + 40 = 100 bricks of snow in the igloo.