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