Xuan and Gwen had an equal number of erasers at first. Xuan used
15 of her erasers and Gwen used
110 of her erasers. They used 12 erasers altogether. How many erasers did Gwen have in the end?
| |
Xuan |
Gwen |
| Before |
5x2 =
10 u |
10x1 =
10 u |
| Change |
- 1x2 =
- 2 u |
- 1x1 =
- 1 u |
| After |
4x2 =
8 u |
9x1 =
9 u |
The number of erasers that Xuan and Gwen each had at first is the same. Make the number of erasers that Xuan and Gwen each had at first the same. LCM of 5 and 10 is 10.
Number of erasers that Xuan and Gwen used
= 2 u + 1 u
= 3 u
3 u = 12
1 u = 12 ÷ 3 = 4
Number of erasers that Gwen had in the end
= 9 u
= 9 x 4
= 36
Answer(s): 36
