In a bookstore, 4 staplers and 5 files cost $25.90. Joseph bought 5 staplers and 6 files at $31.80 from the book shop.
- Find the cost of 1 stapler and 1 file.
- What was the cost of 1 file?
(a)
Let 1 stapler be 1 S.
Let 1 file be 1 F.
4 S + 5 F = 25.90 --- (1)
5 S + 6 F = 31.80 --- (2)
(2) - (1)
1 S + 1 F = 31.80 --- 25.90
1 S + 1 F = 5.90 --- (3)
Cost of 1 stapler and 1 file = $5.90
(b)
(3)
x4 4 S + 4 F = 23.60 --- (4)
(1) - (4)
1 F = 25.90 - 23.60 = $2.30
Cost of 1 file = $2.30
Answer(s): (a) $5.90; (b) $2.30