Neave has a total of 26 of silver and brown notebooks.
15 of the silver notebooks and half of the brown notebooks are new. How many of his brown notebooks are new if he has a total of 7 new notebooks?
| |
Silver notebooks |
Brown notebooks |
Total |
| Total |
5 u |
2 p |
26 |
| New |
1 u |
1 p |
7 |
| Old |
4 u |
1 p |
19 |
Number of old notebooks
= 26 - 7
= 19
1 u + 1 p = 7 --- (1)
4 u + 1 p = 19 --- (2)
(2) - (1)
(4 u + 1 p) - (1 u + 1 p) = 19 - 7
4 u - 1 u = 12
3 u = 12
1 u = 12 ÷ 3 = 4
Number of new brown notebooks
= 7 - 1 u
= 7 - 4
= 3
Answer(s): 3
