Justin had
58 the number of marbles that Sam had at first. After Sam gave Justin 70 of his marbles, Justin had
45 the number of marbles that Sam had. How many marbles did Justin have at first?
|
Justin |
Sam |
Total |
Before |
5x9 = 45 u |
8x9 = 72 u |
13x9 = 117 u |
Change |
+ 7 u |
- 7 u |
|
After |
4x13 = 52 u |
5x13 = 65 u |
9x13 = 117 u |
The total number of marbles that Justin and Sam had at first and in the end remains unchanged. Make the total number of marbles the same. LCM of 13 and 9 is 117.
Number of marbles that Sam gave Justin
= 52 u - 45 u
= 7 u
7 u = 70
1 u = 70 ÷ 7 = 10
Number of marbles that Justin had at first
= 45 u
= 45 x 10
= 450
Answer(s): 450