In a bookstore, 2 staplers and 3 pens cost $16.90. Joseph bought 3 staplers and 4 pens at $23.70 from the book shop.
- Find the cost of 1 stapler and 1 pen.
- What was the cost of 1 pen?
(a)
Let 1 stapler be 1 S.
Let 1 pen be 1 P.
2 S + 3 P = 16.90 --- (1)
3 S + 4 P = 23.70 --- (2)
(2) - (1)
1 S + 1 P = 23.70 --- 16.90
1 S + 1 P = 6.80 --- (3)
Cost of 1 stapler and 1 pen = $6.80
(b)
(3)
x2 2 S + 2 P = 13.60 --- (4)
(1) - (4)
1 P = 16.90 - 13.60 = $3.30
Cost of 1 pen = $3.30
Answer(s): (a) $6.80; (b) $3.30