Joelle and Gem collected marbles. Gem gave 60% of her marbles to Joelle. As a result, Joelle's marbles increased by 20%. If Joelle had 180 marbles left, find the total number of marbles the two girls had at first.
| |
Comparing the change
in Gem's marbles |
Gem |
Joelle |
| Before |
5x1 =
5 u |
|
5x3 =
15 u |
| Change |
- 3x1 =
- 3 u |
- 1x3 =
- 3 u |
+ 1x3 =
+ 3 u |
| After |
2x1 =
2 u |
|
6x3 =
18 u |
60% =
60100 =
35 20% =
20100 =
15 The number of marbles that Joelle gave to Gem is repeated. Make the number of marbles that Joelle gave to Gem the same. LCM of 1 and 3 is 3.
Number of marbles that Joelle had in the end = 18 u
18 u = 180
1 u = 180 ÷ 18 = 10
Number of marbles that Gem and Joelle had at first
= 5 u + 15 u
= 20 u
= 20 x 10
= 200
Answer(s): 200
