In a shop, 3 pencils and 4 markers cost $18.70. Joseph bought 4 pencils and 5 markers at $24.20 from the book shop.
- Find the cost of 1 pencil and 1 marker.
- What was the cost of 1 marker?
(a)
Let 1 pencil be 1 P.
Let 1 marker be 1 M.
3 P + 4 M = 18.70 --- (1)
4 P + 5 M = 24.20 --- (2)
(2) - (1)
1 P + 1 M = 24.20 --- 18.70
1 P + 1 M = 5.50 --- (3)
Cost of 1 pencil and 1 marker = $5.50
(b)
(3)
x3 3 P + 3 M = 16.50 --- (4)
(1) - (4)
1 M = 18.70 - 16.50 = $2.20
Cost of 1 marker = $2.20
Answer(s): (a) $5.50; (b) $2.20