Ken, Sam and Zeph have some erasers. The ratios of their erasers are as follows:
Ken : (Ken + Sam + Zeph) = 2 : 5
Sam : (Ken + Zeph) = 1 : 3
Zeph has 18 erasers more than Sam. In the end, Zeph gives away all he has to Sam and Ken so that both Sam and Ken end up with the same number of erasers, how many erasers has Ken received from Zeph?
Sam |
Zeph |
Ken |
Total |
3x4 |
2x4 |
5x4 |
1x5 |
3x5 |
4x5 |
5 u |
7 u |
8 u |
20 u |
The total number of erasers is repeated. Make the total number of erasers the same. LCM of 5 and 4 is 20.
Number of erasers that Zeph has more than Sam
= 7 u - 5 u
= 2 u
2 u = 18
1 u = 18 ÷ 2 = 9
|
Sam |
Zeph |
Ken |
Before |
5 u |
7 u |
8 u |
Change |
+ 5 u |
- 7 u |
+ 2 u |
After |
10 u |
0 u |
10 u |
Number of erasers that Ken has received from Zeph
= 10 u - 8 u
= 2 u
= 2 x 9
= 18
Answer(s): 18