Zeph has a total of 46 of black and white staplers.
16 of the black staplers and half of the white staplers are new. How many of his white staplers are new if he has a total of 15 new staplers?
| |
Black staplers |
White staplers |
Total |
| Total |
6 u |
2 p |
46 |
| New |
1 u |
1 p |
15 |
| Old |
5 u |
1 p |
31 |
Number of old staplers
= 46 - 15
= 31
1 u + 1 p = 15 --- (1)
5 u + 1 p = 31 --- (2)
(2) - (1)
(5 u + 1 p) - (1 u + 1 p) = 31 - 15
5 u - 1 u = 16
4 u = 16
1 u = 16 ÷ 4 = 4
Number of new white staplers
= 15 - 1 u
= 15 - 4
= 11
Answer(s): 11
