Gabby had four times the number of plastic bricks as Oscar. Gabby used all her bricks to build 10 identical figurines. Oscar used all his bricks to build 5 identical figurines. Gabby used 9 more bricks than Oscar for each figurine. How many bricks did Oscar have?

	Gabby	Oscar
Number	10	5
Value	1 u + 9	1 u
Total value	10 u + 90	5 u

Number of plastic bricks that Oscar used for each figurine = 1 u
Number of plastic bricks that Gabby used for each figurine = 1 u + 9

Number of plastic bricks that Oscar had
= 5 x 1 u
= 5 u

Number of plastic bricks that Gabby had
= 10 x (1 u + 9)
= 10 u + 90

Gabby had four times the number of plastic bricks as Oscar.

4 x 5 u = 10 u + 90
20 u = 10 u + 90
20 u - 10 u = 90
10 u = 90

1 u = 90 ÷ 10 = 9

Number of bricks that Oscar had
= 5 u
= 5 x 9
= 45

Answer(s): 45