The number of purple markers is twice the number of orange markers. The number of orange markers is 9 more than the number of red markers. The total number of markers is 115. The cost of each purple marker is $3.10 and the cost of each red marker is $3.10. The total cost of all the markers is $337.90.
- Find the number of red markers.
- Find the cost of a orange marker.
(a)
Number of red markers = 1 u
Number of orange markers = 1 u + 9
Number of purple markers
= 2(1 u + 9)
= 2 u + 18
Total of number of markers
= 1 u + 1 u + 9 + 2 u + 18
= 4 u + 27
4 u + 27 = 115
4 u = 115 - 27
4 u = 88
1 u = 88 ÷ 4 = 22
Number of red markers
= 1 u
= 22
(b)
Number of red markers = 22
Number of orange markers
= 22 + 9
= 31
Number of purple markers
= 2 x 31
= 62
Cost of red markers
= 22 x 3.10
= $68.20
Cost of purple markers
= 62 x 3.10
= $192.20
Cost of orange markers
= 337.90 - 192.20 - 68.20
= $77.50
Cost of 1 orange marker
= 77.50 ÷ 31
= $2.50
Answer(s) (a) 22; (b) $2.50