In a store, 3 pencils and 4 markers cost $24.70. Joseph bought 4 pencils and 5 markers at $31.80 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 = 24.70 --- (1)
4 P + 5 M = 31.80 --- (2)
(2) - (1)
1 P + 1 M = 31.80 --- 24.70
1 P + 1 M = 7.10 --- (3)
Cost of 1 pencil and 1 marker = $7.10
(b)
(3)
x3 3 P + 3 M = 21.30 --- (4)
(1) - (4)
1 M = 24.70 - 21.30 = $3.40
Cost of 1 marker = $3.40
Answer(s): (a) $7.10; (b) $3.40