Yen and Risa collected beads. Yen gave 10% of her beads to Risa. As a result, Risa's beads increased by 75%. If Yen had 81 beads left, find the total number of beads the two girls had at first.
| |
Yen |
Risa |
Comparing the change
in Risa's beads |
| Before |
10x3 =
30 u |
|
4x1 =
4 u |
| Change |
- 1x3 =
- 3 u |
+ 1x3 =
+ 3 u |
+ 3x1 =
+ 3 u |
| After |
9x3 =
27 u |
|
7x1 =
7 u |
10% =
10100 =
110 75% =
75100 =
34 The number of beads that Yen gave to Risa is repeated. Make the number of beads that Yen gave to Risa the same. LCM of 1 and 3 is 3.
Number of beads that Yen had in the end = 27 u
27 u = 81
1 u = 81 ÷ 27 = 3
Number of beads that Yen and Risa had at first
= 30 u + 4 u
= 34 u
= 34 x 3
= 102
Answer(s): 102
