Barbara spent
45 of her money on 12 pencils and 6 notebooks. The cost of each notebook is 4 times the cost of each pencil. She bought some more pencils with
23 of her remaining money. How many pencils did Barbara buy altogether?
| 12 pencils + 6 notebooks |
Remaining
amount |
Total
amount |
| 4 p = 36 u |
1 p = 9 u |
5 p |
12
pencils |
6
notebooks |
More pencils |
Left |
|
| |
|
2 |
1 |
|
| 12 u |
24 u |
6 u |
|
|
Cost of 1 pencil = 1 u
Cost of 1 notebook = 4 u
Cost of 12 pencils = 12 x 1 u = 12 u
Cost of 6 notebooks = 6 x 4 u = 24 u
Cost of 12 pencils + 6 notebooks
= 12 u + 24 u
= 36 u
4 p = 36 u
1 p = 36 u ÷ 4 = 9 u
Amount of remaining money that Barbara spent on buying more pencils
=
23 x 9 u
= 6 u
Number of pencils that Barbara bought with
23 of her remaining money
= 6 u ÷ 1 u
= 6
Total number of pencils that Barbara bought
= 12 + 6
= 18
Answer(s): 18
