Dana spent
34 of her money on 15 notebooks and 9 files. The cost of each file is 3 times the cost of each notebook. She bought some more notebooks with
12 of her remaining money. How many notebooks did Dana buy altogether?
| 15 notebooks + 9 files |
Remaining
amount |
Total
amount |
| 3 p = 42 u |
1 p = 14 u |
4 p |
15
notebooks |
9
files |
More notebooks |
Left |
|
| |
|
1 |
1 |
|
| 15 u |
27 u |
7 u |
|
|
Cost of 1 notebook = 1 u
Cost of 1 file = 3 u
Cost of 15 notebooks = 15 x 1 u = 15 u
Cost of 9 files = 9 x 3 u = 27 u
Cost of 15 notebooks + 9 files
= 15 u + 27 u
= 42 u
3 p = 42 u
1 p = 42 u ÷ 3 = 14 u
Amount of remaining money that Dana spent on buying more notebooks
=
12 x 14 u
= 7 u
Number of notebooks that Dana bought with
12 of her remaining money
= 7 u ÷ 1 u
= 7
Total number of notebooks that Dana bought
= 15 + 7
= 22
Answer(s): 22
