The number of green staplers is thrice the number of red staplers. The number of red staplers is 5 more than the number of brown staplers. The total number of staplers is 115. The cost of each green stapler is $4.30 and the cost of each brown stapler is $2.20. The total cost of all the staplers is $413.80.
- Find the number of brown staplers.
- Find the cost of a red stapler.
(a)
Number of brown staplers = 1 u
Number of red staplers = 1 u + 5
Number of green 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 = 115
5 u = 115 - 20
5 u = 95
1 u = 95 ÷ 5 = 19
Number of brown staplers
= 1 u
= 19
(b)
Number of brown staplers = 19
Number of red staplers
= 19 + 5
= 24
Number of green staplers
= 3 x 24
= 72
Cost of brown staplers
= 19 x 2.20
= $41.80
Cost of green staplers
= 72 x 4.30
= $309.60
Cost of red staplers
= 413.80 - 309.60 - 41.80
= $62.40
Cost of 1 red stapler
= 62.40 ÷ 24
= $2.60
Answer(s) (a) 19; (b) $2.60
