In a bookstore, 4 markers and 5 files cost $20.10. Joseph bought 5 markers and 6 files at $24.40 from the book shop.
- Find the cost of 1 marker and 1 file.
- What was the cost of 1 file?
(a)
Let 1 marker be 1 M.
Let 1 file be 1 F.
4 M + 5 F = 20.10 --- (1)
5 M + 6 F = 24.40 --- (2)
(2) - (1)
1 M + 1 F = 24.40 --- 20.10
1 M + 1 F = 4.30 --- (3)
Cost of 1 marker and 1 file = $4.30
(b)
(3)
x4 4 M + 4 F = 17.20 --- (4)
(1) - (4)
1 F = 20.10 - 17.20 = $2.90
Cost of 1 file = $2.90
Answer(s): (a) $4.30; (b) $2.90