Ken, Cody and Oliver had 198 pens. After Ken used 8 pens and Cody used
25 of her pens, Ken had twice as many pens left as Cody. Oliver bought another 17 pens, he had four times the number of pens Cody had left. How many pens did Oliver have at first?
| |
Ken |
Cody |
Oliver |
Total |
| Before |
6 u + 8 |
5 u |
12 u - 17 |
198 |
| Change |
- 8 |
- 2 u |
+ 17 |
|
| After |
6 u |
3 u |
12 u |
|
Comparing Ken
and Cody in the end |
2 |
1 |
|
|
Comparing Oliver
and Cody in the end |
|
1 |
4 |
|
Number of pens that Ken had in the end
= 2 x 3 u
= 6 u
Number of pens that Oliver had in the end
= 4 x 3 u
= 12 u
Total number of pens at first
= 6 u + 8 + 5 u + 12 u - 17
= 23 u - 9
23 u - 9 = 198
23 u = 198 + 9
23 u = 207
1 u = 207 ÷ 23 = 9
Number of pens that Oliver had at first
= 12 u - 17
= 12 x 9 - 17
= 108 - 17
= 91
Answer(s): 91
