In a stationery kiosk, 2 pens and 3 notebooks cost $14.40. Joseph bought 3 pens and 4 notebooks at $19.80 from the book shop.
- Find the cost of 1 pen and 1 notebook.
- What was the cost of 1 notebook?
(a)
Let 1 pen be 1 P.
Let 1 notebook be 1 N.
2 P + 3 N = 14.40 --- (1)
3 P + 4 N = 19.80 --- (2)
(2) - (1)
1 P + 1 N = 19.80 --- 14.40
1 P + 1 N = 5.40 --- (3)
Cost of 1 pen and 1 notebook = $5.40
(b)
(3)
x2 2 P + 2 N = 10.80 --- (4)
(1) - (4)
1 N = 14.40 - 10.80 = $3.60
Cost of 1 notebook = $3.60
Answer(s): (a) $5.40; (b) $3.60