Cindy and Gem had an equal number of pens at first. Cindy used
13 of her pens and Gem used
110 of her pens. They used 78 pens altogether. How many pens did Gem have in the end?
| |
Cindy |
Gem |
| Before |
3x10 =
30 u |
10x3 =
30 u |
| Change |
- 1x10 =
- 10 u |
- 1x3 =
- 3 u |
| After |
2x10 =
20 u |
9x3 =
27 u |
The number of pens that Cindy and Gem each had at first is the same. Make the number of pens that Cindy and Gem each had at first the same. LCM of 3 and 10 is 30.
Number of pens that Cindy and Gem used
= 10 u + 3 u
= 13 u
13 u = 78
1 u = 78 ÷ 13 = 6
Number of pens that Gem had in the end
= 27 u
= 27 x 6
= 162
Answer(s): 162
