Glen has a total of 58 of pink and brown files.
14 of the pink files and half of the brown files are new. How many of his brown files are new if he has a total of 19 new files?
| |
Pink files |
Brown files |
Total |
| Total |
4 u |
2 p |
58 |
| New |
1 u |
1 p |
19 |
| Old |
3 u |
1 p |
39 |
Number of old files
= 58 - 19
= 39
1 u + 1 p = 19 --- (1)
3 u + 1 p = 39 --- (2)
(2) - (1)
(3 u + 1 p) - (1 u + 1 p) = 39 - 19
3 u - 1 u = 20
2 u = 20
1 u = 20 ÷ 2 = 10
Number of new brown files
= 19 - 1 u
= 19 - 10
= 9
Answer(s): 9
