John, David and Corwin collected pens in the ratio of 8 : 9 : 10. After Corwin gave
710 to John and David, Corwin had 300 less pens than John. The number of pens that David had increased by 50%. How many pens did John and Corwin have in the end?
| |
John |
David |
Corwin |
| Before |
8 u |
9 u |
10 u |
| Change |
+ 2.5 u |
+ 4.5 u |
- 7 u |
| After |
10.5 u |
13.5 u |
3 u |
Number of pens that Corwin gave to John and David
=
710 x 10 u
= 7 u
Number of pens that David received from Corwin
=
50100 x 9 u
= 4.5 u
Number of pens that John received from Corwin
= 7 u - 4.5 u
= 2.5 u
Number of less pens that Corwin had less than John
= 10.5 u - 3 u
= 7.5 u
7.5 u = 300
1 u = 300 ÷ 7.5 = 40
Number of pens that John and Corwin had
= 10.5 u + 3 u
= 13.5 u
= 13.5 x 40
= 540
Answer(s): 540
