The pencil cost twice as much as the notebook. Luke bought 1 pencil and 3 notebooks for $20.
- How much did one notebook cost?
- How much did one pencil cost?
(a)
Cost of the notebook = 1 u
Cost of 3 notebooks = 3 x 1 u = 3 u
Cost of the pencil = 2 x 1 u = 2 u
Total cost = 3 u + 2 u = 5 u
5 u = 20
1 u = 20 ÷ 5 = 4
Cost of 1 notebook
= 1 u
= $4
(b)
Cost of 1 pencil
= 2 u
= 2 x 4
= $8
Answer(s): (a) $4; (b)$8