Last Thursday, Luis had twice as many beads as Luke. Today, Luis gives 21 of his beads to his neighbour. Now, Luke has four times as many beads as Luis. How many beads does Luke have?
| |
Luis |
Luke |
| Before |
2x4 =
8 u |
1x4 =
4 u |
| Change |
- 21 |
|
| After |
1 u |
4 u |
The number of beads that Luke had at first and in the end remains unchanged. Make the number of beads that Luke has the same. LCM of 1 and 4 is 4.
Number of beads that Luis gives to his neighbour
= 8 u - 1 u
= 7 u
7 u = 21
1 u = 21 ÷ 7 = 3
Number of beads that Luke has
= 4 u
= 4 x 3
= 12
Answer(s): 12
