Cathy had 100 more marbles than Eva. After Eva gave away
25 of her marbles, Cathy had five times as many marbles as Eva. How many marbles did Eva have at first?
| |
Cathy |
Eva |
Comparing Cathy and
Eva at first |
100 more |
|
| Before |
15 u |
5 u |
| Change |
|
- 2 u |
| After |
15 u |
3 u |
Comparing Cathy and
Eva in the end |
5x3 =
15 u |
1x3 =
3 u |
Number of marbles that Eva had in the end is repeated. Make the number of marbles that Eva had in the end the same. LCM of 1 and 3 is 3.
Number of marbles that Cathy had at first = 15 u
Number of marbles that Cathy had more than Eva at first
= 15 u - 5 u
= 10 u
10 u = 100
1 u = 100 ÷ 10 = 10
Number of marbles that Eva had at first
= 5 u
= 5 x 10
= 50
Answer(s): 50
