Vincent has a total of 58 of yellow and black files.
14 of the yellow files and half of the black files are new. How many of his black files are new if he has a total of 17 new files?
| |
Yellow files |
Black files |
Total |
| Total |
4 u |
2 p |
58 |
| New |
1 u |
1 p |
17 |
| Old |
3 u |
1 p |
41 |
Number of old files
= 58 - 17
= 41
1 u + 1 p = 17 --- (1)
3 u + 1 p = 41 --- (2)
(2) - (1)
(3 u + 1 p) - (1 u + 1 p) = 41 - 17
3 u - 1 u = 24
2 u = 24
1 u = 24 ÷ 2 = 12
Number of new black files
= 17 - 1 u
= 17 - 12
= 5
Answer(s): 5
