In a bookstore, 4 files and 5 markers cost $20.90. Joseph bought 5 files and 6 markers at $25.70 from the book shop.
- Find the cost of 1 file and 1 marker.
- What was the cost of 1 marker?
(a)
Let 1 file be 1 F.
Let 1 marker be 1 M.
4 F + 5 M = 20.90 --- (1)
5 F + 6 M = 25.70 --- (2)
(2) - (1)
1 F + 1 M = 25.70 --- 20.90
1 F + 1 M = 4.80 --- (3)
Cost of 1 file and 1 marker = $4.80
(b)
(3)
x4 4 F + 4 M = 19.20 --- (4)
(1) - (4)
1 M = 20.90 - 19.20 = $1.70
Cost of 1 marker = $1.70
Answer(s): (a) $4.80; (b) $1.70