Elyse has 4 times as many beads as Joelle. Joelle has
47 as many beads as Risa. If the three of them have a total of 81 beads, how many beads does Risa have?
Elyse |
Joelle |
Risa |
4x4 |
1x4 |
|
|
4x1 |
7x1 |
16 u |
4 u |
7 u |
The number of beads that Joelle has is repeated. Make the number of beads that Joelle has the same. LCM of 1 and 4 is 4.
Total number of beads that the three of them have
= 16 u + 4 u + 7 u
= 27 u
27 u = 81
1 u = 81 ÷ 27 = 3
Number of beads that Risa has
= 7 u
= 7 x 3
= 21
Answer(s): 21