Mark had
25 the number of stickers that Luke had at first. After Luke gave Mark 90 of his stickers, Mark had
45 the number of stickers that Luke had. How many stickers did Mark have at first?
|
Mark |
Luke |
Total |
Before |
2x9 = 18 u |
5x9 = 45 u |
7x9 = 63 u |
Change |
+ 10 u |
- 10 u |
|
After |
4x7 = 28 u |
5x7 = 35 u |
9x7 = 63 u |
The total number of stickers that Mark and Luke had at first and in the end remains unchanged. Make the total number of stickers the same. LCM of 7 and 9 is 63.
Number of stickers that Luke gave Mark
= 28 u - 18 u
= 10 u
10 u = 90
1 u = 90 ÷ 10 = 9
Number of stickers that Mark had at first
= 18 u
= 18 x 9
= 162
Answer(s): 162