Tommy and Cody had 51 pens together. Cody had 3 less pens than Tommy. Both of them sold some of their pens. Cody sold 20% more pens than what Tommy sold. In the end, Cody had half as many pens left as Tommy. How many pens had Cody left?
| |
Tommy
(1) |
Cody
(2) |
Make p the same
(2)x2 = (3) |
Comparing Tommy
and Cody at first |
3 more |
|
|
| Before |
27 |
24 |
48 |
| Change |
- 5 u |
- 6 u |
- 12 u |
| After |
2 p |
1 p |
2 p |
Number of pens that Cody had at first
= (51 - 3) ÷ 2
= 48 ÷ 2
= 24
Number of pens that Tommy had at first
= 24 + 3
= 27
Number of pens that Cody sold in percent
= 100% + 20%
= 120%
120% =
120100 =
65 Make p the same.
(1) = (3)
27 - 5 u = 48 - 12 u
12 u - 5 u = 48 - 27
7 u = 21
1 u = 21 ÷ 7 = 3
Number of pens that Cody had left
= 24 - 6 u
= 24 - 6 x 3
= 24 - 18
= 6
Answer(s): 6
