Carl and Bryan had 60 pens together. Carl had 18 more pens than Bryan. Both of them sold some of their pens. Bryan sold 40% less pens than what Carl sold. In the end, Bryan had half as many pens left as Carl. How many pens had Carl left?
| |
Carl
(1) |
Bryan
(2) |
Make p the same
(2)x2 = (3) |
Comparing Carl
and Bryan at first |
18 more |
|
|
| Before |
39 |
21 |
42 |
| Change |
- 5 u |
- 3 u |
- 6 u |
| After |
2 p |
1 p |
2 p |
Number of pens that Bryan had at first
= (60 - 18) ÷ 2
= 42 ÷ 2
= 21
Number of pens that Carl had at first
= 21 + 18
= 39
Number of pens that Bryan sold in percent
= 100% - 40%
= 60%
60% =
60100 =
35 Make p the same.
(1) = (3)
39 - 5 u = 42 - 6 u
6 u - 5 u = 42 - 39
1 u = 3
1 u = 3 ÷ 1 = 3
Number of pens that Carl had left
= 39 - 5 u
= 39 - 5 x 3
= 39 - 15
= 24
Answer(s): 24
