In a book shop, 2 pencils and 3 notebooks cost $6.60. Joseph bought 3 pencils and 4 notebooks at $9.30 from the book shop.
- Find the cost of 1 pencil and 1 notebook.
- What was the cost of 1 notebook?
(a)
Let 1 pencil be 1 P.
Let 1 notebook be 1 N.
2 P + 3 N = 6.60 --- (1)
3 P + 4 N = 9.30 --- (2)
(2) - (1)
1 P + 1 N = 9.30 --- 6.60
1 P + 1 N = 2.70 --- (3)
Cost of 1 pencil and 1 notebook = $2.70
(b)
(3)
x2 2 P + 2 N = 5.40 --- (4)
(1) - (4)
1 N = 6.60 - 5.40 = $1.20
Cost of 1 notebook = $1.20
Answer(s): (a) $2.70; (b) $1.20