Risa has 6 times as many cookies as Pamela. The total number of Risa's and Pamela's cookies is 8 times of Gabby's. Risa and Pamela have 490 cookies more than Gabby's. How many more cookies does Risa have than Pamela?
| Risa |
Pamela |
Gabby |
| 6x8 |
1x8 |
|
| 8x7 |
1x7 |
| 48 u |
8 u |
7 u |
The total number of cookies that Risa and Pamela have is repeated. Make the total number of cookies that Risa and Pamela have the same. LCM of 7 and 8 is 56.
Total number of cookies that Risa and Pamela have
= 48 u + 8 u
= 56 u
Number of more cookies that Risa and Pamela have than Gabby
= 56 u - 7 u
= 49 u
49 u = 490
1 u = 490 ÷ 49 = 10
Number of more cookies that Risa has than Pamela
= 48 u - 8 u
= 40 u
= 40 x 10
= 400
Answer(s): 400
