Diana spent
23 of her money on 13 files and 5 notebooks. The cost of each notebook is 3 times the cost of each file. She bought some more files with
12 of her remaining money. How many files did Diana buy altogether?
| 13 files + 5 notebooks |
Remaining
amount |
Total
amount |
| 2 p = 28 u |
1 p = 14 u |
3 p |
13
files |
5
notebooks |
More files |
Left |
|
| |
|
1 |
1 |
|
| 13 u |
15 u |
7 u |
|
|
Cost of 1 file = 1 u
Cost of 1 notebook = 3 u
Cost of 13 files = 13 x 1 u = 13 u
Cost of 5 notebooks = 5 x 3 u = 15 u
Cost of 13 files + 5 notebooks
= 13 u + 15 u
= 28 u
2 p = 28 u
1 p = 28 u ÷ 2 = 14 u
Amount of remaining money that Diana spent on buying more files
=
12 x 14 u
= 7 u
Number of files that Diana bought with
12 of her remaining money
= 7 u ÷ 1 u
= 7
Total number of files that Diana bought
= 13 + 7
= 20
Answer(s): 20
