Min spent
37 of her money on 7 punchers and 5 files. The cost of one file was four times the cost of one puncher. She bought some more files with
13 of her remaining money. How many files did Min buy altogether?
7 punchers and
5 files |
Remaining amount |
| 3x3 |
4x3 |
| |
More files |
Left |
| |
1x4 |
2x4 |
| 9 p |
4 p |
8 p |
Cost of 1 puncher = 1 u
Cost of 1 file = 4 u
Cost of 7 punchers = 7 x 1 u = 7 u
Cost of 5 files = 5 x 4 u = 20 u
Total cost of 7 punchers and 5 files
= 7 u + 20 u
= 27 u
9 p = 27 u
1 p = 27 ÷ 9 = 3 u
Amount that Min used to buy more files
= 4 p
= 4 x 3 u
= 12 u
Number of more files that Min bought
= 12 u ÷ 4 u
= 3
Total number of files that Min bought
= 5 + 3
= 8
Answer(s): 8
