Seth and Perry had some stamps in the ratio of 11 : 10. Perry and Cole had some stamps in the ratio of 7 : 2. Seth sold 252 stamps to Cole and ended up with half the number of stamps Perry had. How many stamps did Cole have in the end?
| Seth |
Perry |
Cole |
| 11x7 |
10x7 |
|
| |
7x10 |
2x10 |
| 77 u |
70 u |
20 u |
The number of stamps that Perry had at first is repeated. Make the number of stamps that Perry had at first the same. LCM of 10 and 7 is 70.
| |
Seth |
Perry |
Cole |
| Before |
77 u |
70 u |
20 u |
| Change |
- 252 |
|
+ 252 |
| After |
35 u |
70 u |
20 u + 252 |
Number of stamps that Seth had in the end
= 70 u ÷ 2
= 35 u
Number of stamps that Seth sold to Cole
= 77 u - 35 u
= 42 u
42 u = 252
1 u = 252 ÷ 42 = 6
Number of stamps that Cole had in the end
= 20 u + 252
= 20 x 6 + 252
= 120 + 252
= 372
Answer(s): 372
