The number of blue markers is four times the number of red markers. The number of red markers is 7 more than the number of purple markers. The total number of markers is 107. The cost of each blue marker is $2.70 and the cost of each purple marker is $3.30. The total cost of all the markers is $269.50.
- Find the number of purple markers.
- Find the cost of a red marker.
(a)
Number of purple markers = 1 u
Number of red markers = 1 u + 7
Number of blue markers
= 4(1 u + 7)
= 4 u + 28
Total of number of markers
= 1 u + 1 u + 7 + 4 u + 28
= 6 u + 35
6 u + 35 = 107
6 u = 107 - 35
6 u = 72
1 u = 72 ÷ 6 = 12
Number of purple markers
= 1 u
= 12
(b)
Number of purple markers = 12
Number of red markers
= 12 + 7
= 19
Number of blue markers
= 4 x 19
= 76
Cost of purple markers
= 12 x 3.30
= $39.60
Cost of blue markers
= 76 x 2.70
= $205.20
Cost of red markers
= 269.50 - 205.20 - 39.60
= $24.70
Cost of 1 red marker
= 24.70 ÷ 19
= $1.30
Answer(s) (a) 12; (b) $1.30
