Ben has a total of 62 of red and yellow pencils.
15 of the red pencils and half of the yellow pencils are new. How many of his yellow pencils are new if he has a total of 19 new pencils?
| |
Red pencils |
Yellow pencils |
Total |
| Total |
5 u |
2 p |
62 |
| New |
1 u |
1 p |
19 |
| Old |
4 u |
1 p |
43 |
Number of old pencils
= 62 - 19
= 43
1 u + 1 p = 19 --- (1)
4 u + 1 p = 43 --- (2)
(2) - (1)
(4 u + 1 p) - (1 u + 1 p) = 43 - 19
4 u - 1 u = 24
3 u = 24
1 u = 24 ÷ 3 = 8
Number of new yellow pencils
= 19 - 1 u
= 19 - 8
= 11
Answer(s): 11
