Barbara had thrice the number of plastic blocks as Michael. Barbara used all her blocks to build 12 identical figurines. Michael used all his blocks to build 5 identical figurines. Barbara used 9 more blocks than Michael for each figurine. How many blocks did Michael have?

	Barbara	Michael
Number	12	5
Value	1 u + 9	1 u
Total value	12 u + 108	5 u

Number of plastic blocks that Michael used for each figurine = 1 u
Number of plastic blocks that Barbara used for each figurine = 1 u + 9

Number of plastic blocks that Michael had
= 5 x 1 u
= 5 u

Number of plastic blocks that Barbara had
= 12 x (1 u + 9)
= 12 u + 108

Barbara had thrice the number of plastic blocks as Michael.

3 x 5 u = 12 u + 108
15 u = 12 u + 108
15 u - 12 u = 108
3 u = 108

1 u = 108 ÷ 3 = 36

Number of blocks that Michael had
= 5 u
= 5 x 36
= 180

Answer(s): 180