Nick has a total of 58 of red and grey pencils.
15 of the red pencils and half of the grey pencils are new. How many of his grey pencils are new if he has a total of 14 new pencils?
| |
Red pencils |
Grey pencils |
Total |
| Total |
5 u |
2 p |
58 |
| New |
1 u |
1 p |
14 |
| Old |
4 u |
1 p |
44 |
Number of old pencils
= 58 - 14
= 44
1 u + 1 p = 14 --- (1)
4 u + 1 p = 44 --- (2)
(2) - (1)
(4 u + 1 p) - (1 u + 1 p) = 44 - 14
4 u - 1 u = 30
3 u = 30
1 u = 30 ÷ 3 = 10
Number of new grey pencils
= 14 - 1 u
= 14 - 10
= 4
Answer(s): 4
