Elyse had twice the number of metallic bricks as Eric. Elyse used all her bricks to build 8 identical houses. Eric used all his bricks to build 5 identical houses. Elyse used 9 more bricks than Eric for each house. How many bricks did Eric have?

	Elyse	Eric
Number	8	5
Value	1 u + 9	1 u
Total value	8 u + 72	5 u

Number of metallic bricks that Eric used for each house = 1 u
Number of metallic bricks that Elyse used for each house = 1 u + 9

Number of metallic bricks that Eric had
= 5 x 1 u
= 5 u

Number of metallic bricks that Elyse had
= 8 x (1 u + 9)
= 8 u + 72

Elyse had twice the number of metallic bricks as Eric.

2 x 5 u = 8 u + 72
10 u = 8 u + 72
10 u - 8 u = 72
2 u = 72

1 u = 72 ÷ 2 = 36

Number of bricks that Eric had
= 5 u
= 5 x 36
= 180

Answer(s): 180