The number of red staplers is thrice the number of orange staplers. The number of orange staplers is 10 more than the number of yellow staplers. The total number of staplers is 115. The cost of each red stapler is $2.50 and the cost of each yellow stapler is $1.70. The total cost of all the staplers is $275.50.
- Find the number of yellow staplers.
- Find the cost of a orange stapler.
(a)
Number of yellow staplers = 1 u
Number of orange staplers = 1 u + 10
Number of red staplers
= 3(1 u + 10)
= 3 u + 30
Total of number of staplers
= 1 u + 1 u + 10 + 3 u + 30
= 5 u + 40
5 u + 40 = 115
5 u = 115 - 40
5 u = 75
1 u = 75 ÷ 5 = 15
Number of yellow staplers
= 1 u
= 15
(b)
Number of yellow staplers = 15
Number of orange staplers
= 15 + 10
= 25
Number of red staplers
= 3 x 25
= 75
Cost of yellow staplers
= 15 x 1.70
= $25.50
Cost of red staplers
= 75 x 2.50
= $187.50
Cost of orange staplers
= 275.50 - 187.50 - 25.50
= $62.50
Cost of 1 orange stapler
= 62.50 ÷ 25
= $2.50
Answer(s) (a) 15; (b) $2.50
