Hilda had five times the number of plastic bricks as Rael. Hilda used all her bricks to build 12 identical cars. Rael used all his bricks to build 6 identical cars. Hilda used 9 more bricks than Rael for each car. How many bricks did Rael have?

	Hilda	Rael
Number	12	6
Value	1 u + 9	1 u
Total value	12 u + 108	6 u

Number of plastic bricks that Rael used for each car = 1 u
Number of plastic bricks that Hilda used for each car = 1 u + 9

Number of plastic bricks that Rael had
= 6 x 1 u
= 6 u

Number of plastic bricks that Hilda had
= 12 x (1 u + 9)
= 12 u + 108

Hilda had five times the number of plastic bricks as Rael.

5 x 6 u = 12 u + 108
30 u = 12 u + 108
30 u - 12 u = 108
18 u = 108

1 u = 108 ÷ 18 = 6

Number of bricks that Rael had
= 6 u
= 6 x 6
= 36

Answer(s): 36