Ian, Cole and Tommy had 66 pens. After Ian used 5 pens and Cole used
56 of her pens, Ian had twice as many pens left as Cole. Tommy bought another 11 pens, he had four times the number of pens Cole had left. How many pens did Tommy have at first?
| |
Ian |
Cole |
Tommy |
Total |
| Before |
2 u + 5 |
6 u |
4 u - 11 |
66 |
| Change |
- 5 |
- 5 u |
+ 11 |
|
| After |
2 u |
1 u |
4 u |
|
Comparing Ian
and Cole in the end |
2 |
1 |
|
|
Comparing Tommy
and Cole in the end |
|
1 |
4 |
|
Number of pens that Ian had in the end
= 2 x 1 u
= 2 u
Number of pens that Tommy had in the end
= 4 x 1 u
= 4 u
Total number of pens at first
= 2 u + 5 + 6 u + 4 u - 11
= 12 u - 6
12 u - 6 = 66
12 u = 66 + 6
12 u = 72
1 u = 72 ÷ 12 = 6
Number of pens that Tommy had at first
= 4 u - 11
= 4 x 6 - 11
= 24 - 11
= 13
Answer(s): 13
