Archie has a total of 53 of brown and white staplers.
13 of the brown staplers and half of the white staplers are new. How many of his white staplers are new if he has a total of 21 new staplers?
| |
Brown staplers |
White staplers |
Total |
| Total |
3 u |
2 p |
53 |
| New |
1 u |
1 p |
21 |
| Old |
2 u |
1 p |
32 |
Number of old staplers
= 53 - 21
= 32
1 u + 1 p = 21 --- (1)
2 u + 1 p = 32 --- (2)
(2) - (1)
(2 u + 1 p) - (1 u + 1 p) = 32 - 21
2 u - 1 u = 11
1 u = 11
1 u = 11 ÷ 1 = 11
Number of new white staplers
= 21 - 1 u
= 21 - 11
= 10
Answer(s): 10
