Last Tuesday, Warren had twice as many marbles as Zane. Today, Warren gives 30 of his marbles to his brother. Now, Zane has twice as many marbles as Warren. How many marbles does Zane have?
| |
Warren |
Zane |
| Before |
2x2 =
4 u |
1x2 =
2 u |
| Change |
- 30 |
|
| After |
1 u |
2 u |
The number of marbles that Zane had at first and in the end remains unchanged. Make the number of marbles that Zane has the same. LCM of 1 and 2 is 2.
Number of marbles that Warren gives to his brother
= 4 u - 1 u
= 3 u
3 u = 30
1 u = 30 ÷ 3 = 10
Number of marbles that Zane has
= 2 u
= 2 x 10
= 20
Answer(s): 20
