Cody and Ben had 84 pens together. Cody had 12 more pens than Ben. Both of them sold some of their pens. Ben sold 20% less pens than what Cody sold. In the end, Ben had half as many pens left as Cody. How many pens had Cody left?
| |
Cody
(1) |
Ben
(2) |
Make p the same
(2)x2 = (3) |
Comparing Cody
and Ben at first |
12 more |
|
|
| Before |
48 |
36 |
72 |
| Change |
- 5 u |
- 4 u |
- 8 u |
| After |
2 p |
1 p |
2 p |
Number of pens that Ben had at first
= (84 - 12) ÷ 2
= 72 ÷ 2
= 36
Number of pens that Cody had at first
= 36 + 12
= 48
Number of pens that Ben sold in percent
= 100% - 20%
= 80%
80% =
80100 =
45 Make p the same.
(1) = (3)
48 - 5 u = 72 - 8 u
8 u - 5 u = 72 - 48
3 u = 24
1 u = 24 ÷ 3 = 8
Number of pens that Cody had left
= 48 - 5 u
= 48 - 5 x 8
= 48 - 40
= 8
Answer(s): 8
