Rachel and Mary had an equal number of stickers at first. Rachel used
12 of her stickers and Mary used
17 of her stickers. They used 45 stickers altogether. How many stickers did Mary have in the end?
| |
Rachel |
Mary |
| Before |
2x7 =
14 u |
7x2 =
14 u |
| Change |
- 1x7 =
- 7 u |
- 1x2 =
- 2 u |
| After |
1x7 =
7 u |
6x2 =
12 u |
The number of stickers that Rachel and Mary each had at first is the same. Make the number of stickers that Rachel and Mary each had at first the same. LCM of 2 and 7 is 14.
Number of stickers that Rachel and Mary used
= 7 u + 2 u
= 9 u
9 u = 45
1 u = 45 ÷ 9 = 5
Number of stickers that Mary had in the end
= 12 u
= 12 x 5
= 60
Answer(s): 60
