The number of purple markers is twice the number of brown markers. The number of brown markers is 10 more than the number of blue markers. The total number of markers is 134. The cost of each purple marker is $2.80 and the cost of each blue marker is $2.30. The total cost of all the markers is $322.60.

1. Find the number of blue markers.
2. Find the cost of a brown marker.

(a)
Number of blue markers = 1 u
Number of brown markers = 1 u + 10

Number of purple markers
= 2(1 u + 10)
= 2 u + 20

Total of number of markers
= 1 u + 1 u + 10 + 2 u + 20
= 4 u + 30

4 u + 30 = 134
4 u = 134 - 30
4 u = 104

1 u = 104 ÷ 4 = 26

Number of blue markers
= 1 u
= 26

(b)
Number of blue markers = 26

Number of brown markers
=  26 + 10
= 36

Number of purple markers
= 2 x 36
= 72

Cost of blue markers 
= 26 x 2.30
= $59.80

Cost of purple markers 
= 72 x 2.80
= $201.60

Cost of brown markers
= 322.60 - 201.60 - 59.80
= $61.20

Cost of 1 brown marker
= 61.20 ÷ 36
= $1.70

Answer(s) (a) 26; (b) $1.70