The number of orange markers is thrice the number of red markers. The number of red markers is 8 more than the number of green markers. The total number of markers is 127. The cost of each orange marker is $3.70 and the cost of each green marker is $2.80. The total cost of all the markers is $393.40.

1. Find the number of green markers.
2. Find the cost of a red marker.

(a)
Number of green markers = 1 u
Number of red markers = 1 u + 8

Number of orange markers
= 3(1 u + 8)
= 3 u + 24

Total of number of markers
= 1 u + 1 u + 8 + 3 u + 24
= 5 u + 32

5 u + 32 = 127
5 u = 127 - 32
5 u = 95

1 u = 95 ÷ 5 = 19

Number of green markers
= 1 u
= 19

(b)
Number of green markers = 19

Number of red markers
=  19 + 8
= 27

Number of orange markers
= 3 x 27
= 81

Cost of green markers 
= 19 x 2.80
= $53.20

Cost of orange markers 
= 81 x 3.70
= $299.70

Cost of red markers
= 393.40 - 299.70 - 53.20
= $40.50

Cost of 1 red marker
= 40.50 ÷ 27
= $1.50

Answer(s) (a) 19; (b) $1.50