Ivan has a total of 18 of yellow and silver markers.
13 of the yellow markers and half of the silver markers are new. How many of his silver markers are new if he has a total of 7 new markers?
| |
Yellow markers |
Silver markers |
Total |
| Total |
3 u |
2 p |
18 |
| New |
1 u |
1 p |
7 |
| Old |
2 u |
1 p |
11 |
Number of old markers
= 18 - 7
= 11
1 u + 1 p = 7 --- (1)
2 u + 1 p = 11 --- (2)
(2) - (1)
(2 u + 1 p) - (1 u + 1 p) = 11 - 7
2 u - 1 u = 4
1 u = 4
1 u = 4 ÷ 1 = 4
Number of new silver markers
= 7 - 1 u
= 7 - 4
= 3
Answer(s): 3
