Michael has a total of 28 of red and pink pencils.
14 of the red pencils and half of the pink pencils are new. How many of his pink pencils are new if he has a total of 9 new pencils?
| |
Red pencils |
Pink pencils |
Total |
| Total |
4 u |
2 p |
28 |
| New |
1 u |
1 p |
9 |
| Old |
3 u |
1 p |
19 |
Number of old pencils
= 28 - 9
= 19
1 u + 1 p = 9 --- (1)
3 u + 1 p = 19 --- (2)
(2) - (1)
(3 u + 1 p) - (1 u + 1 p) = 19 - 9
3 u - 1 u = 10
2 u = 10
1 u = 10 ÷ 2 = 5
Number of new pink pencils
= 9 - 1 u
= 9 - 5
= 4
Answer(s): 4
