The number of brown staplers is thrice the number of yellow staplers. The number of yellow staplers is 5 more than the number of red staplers. The total number of staplers is 105. The cost of each brown stapler is $3.20 and the cost of each red stapler is $2.70. The total cost of all the staplers is $307.70.
- Find the number of red staplers.
- Find the cost of a yellow stapler.
(a)
Number of red staplers = 1 u
Number of yellow staplers = 1 u + 5
Number of brown staplers
= 3(1 u + 5)
= 3 u + 15
Total of number of staplers
= 1 u + 1 u + 5 + 3 u + 15
= 5 u + 20
5 u + 20 = 105
5 u = 105 - 20
5 u = 85
1 u = 85 ÷ 5 = 17
Number of red staplers
= 1 u
= 17
(b)
Number of red staplers = 17
Number of yellow staplers
= 17 + 5
= 22
Number of brown staplers
= 3 x 22
= 66
Cost of red staplers
= 17 x 2.70
= $45.90
Cost of brown staplers
= 66 x 3.20
= $211.20
Cost of yellow staplers
= 307.70 - 211.20 - 45.90
= $50.60
Cost of 1 yellow stapler
= 50.60 ÷ 22
= $2.30
Answer(s) (a) 17; (b) $2.30
