Ben had
34 as many marbles as Michael. Michael had
47 as many marbles as Lucy. After Ben and Lucy gave 4 marbles to Michael, Michael had thrice as many marbles as Ben. Lucy then had the same number of marbles as Michael.
- What was the ratio of the number of marbles Lucy had to the number of marbles Ben had in the beginning? Answer in simplest form.
- How many marbles did Michael have in the end?
Ben |
Michael |
Lucy |
3 |
4 |
|
|
4 |
7 |
3 |
4 |
7 |
(a)
The number of marbles that Michael is repeated.
Ratio of the number of marbles that Lucy had to the number of marbles that Ben had in the beginning = 7 : 3
|
Ben |
Michael |
Lucy |
Total |
Before |
3x1 = 3 u |
4x1 = 4 u |
7x1 = 7 u |
14x1 = 14 u |
Change |
- 4 |
+ 8 |
- 4 |
|
After |
1x2 = 2 u |
3x2 = 6 u |
3x2 = 6 u |
7x2 = 14 u |
The total number of marbles at first and in the end remains unchanged. Make the total number of marbles the same. LCM of 14 and 7 is 14.
Number of marbles that Michael received from Ben and Lucy
= 2 x 4
= 8
Number of marbles that Michael received from Ben and Lucy
= 2 x 1 u
= 2 u
2 u = 4
1 u = 4 ÷ 2 = 2
Number of marbles that Ashley had in the end
= 6 u
= 6 x 2
= 12
Answer(s): (a) 7 : 3; (b) 12