Cody has a total of 48 of brown and black staplers.
14 of the brown staplers and half of the black staplers are new. How many of his black staplers are new if he has a total of 13 new staplers?
| |
Brown staplers |
Black staplers |
Total |
| Total |
4 u |
2 p |
48 |
| New |
1 u |
1 p |
13 |
| Old |
3 u |
1 p |
35 |
Number of old staplers
= 48 - 13
= 35
1 u + 1 p = 13 --- (1)
3 u + 1 p = 35 --- (2)
(2) - (1)
(3 u + 1 p) - (1 u + 1 p) = 35 - 13
3 u - 1 u = 22
2 u = 22
1 u = 22 ÷ 2 = 11
Number of new black staplers
= 13 - 1 u
= 13 - 11
= 2
Answer(s): 2
