Billy had
34 as many stamps as Bobby. Bobby had
47 as many stamps as Lucy. After Billy and Lucy gave 28 stamps to Bobby, Bobby had thrice as many stamps as Billy. Lucy then had the same number of stamps as Bobby.
- What was the ratio of the number of stamps Lucy had to the number of stamps Billy had in the beginning? Answer in simplest form.
- How many stamps did Bobby have in the end?
Billy |
Bobby |
Lucy |
3 |
4 |
|
|
4 |
7 |
3 |
4 |
7 |
(a)
The number of stamps that Bobby is repeated.
Ratio of the number of stamps that Lucy had to the number of stamps that Billy had in the beginning = 7 : 3
|
Billy |
Bobby |
Lucy |
Total |
Before |
3x1 = 3 u |
4x1 = 4 u |
7x1 = 7 u |
14x1 = 14 u |
Change |
- 28 |
+ 56 |
- 28 |
|
After |
1x2 = 2 u |
3x2 = 6 u |
3x2 = 6 u |
7x2 = 14 u |
The total number of stamps at first and in the end remains unchanged. Make the total number of stamps the same. LCM of 14 and 7 is 14.
Number of stamps that Bobby received from Billy and Lucy
= 2 x 28
= 56
Number of stamps that Bobby received from Billy and Lucy
= 2 x 1 u
= 2 u
2 u = 28
1 u = 28 ÷ 2 = 14
Number of stamps that Ashley had in the end
= 6 u
= 6 x 14
= 84
Answer(s): (a) 7 : 3; (b) 84