Gem and Yen collected erasers. Yen gave 70% of her erasers to Gem. As a result, Gem's erasers increased by 30%. If Gem had 182 erasers left, find the total number of erasers the two girls had at first.
| |
Comparing the change
in Yen's erasers |
Yen |
Gem |
| Before |
10x3 =
30 u |
|
10x7 =
70 u |
| Change |
- 7x3 =
- 21 u |
- 3x7 =
- 21 u |
+ 3x7 =
+ 21 u |
| After |
3x3 =
9 u |
|
13x7 =
91 u |
70% =
70100 =
710 30% =
30100 =
310 The number of erasers that Gem gave to Yen is repeated. Make the number of erasers that Gem gave to Yen the same. LCM of 3 and 7 is 21.
Number of erasers that Gem had in the end = 91 u
91 u = 182
1 u = 182 ÷ 91 = 2
Number of erasers that Yen and Gem had at first
= 30 u + 70 u
= 100 u
= 100 x 2
= 200
Answer(s): 200
