Mary has 3 times as many cookies as Natalie. The total number of Mary's and Natalie's cookies is 7 times of Sarah's. Mary and Natalie have 288 cookies more than Sarah's. How many more cookies does Mary have than Natalie?
| Mary |
Natalie |
Sarah |
| 3x7 |
1x7 |
|
| 7x4 |
1x4 |
| 21 u |
7 u |
4 u |
The total number of cookies that Mary and Natalie have is repeated. Make the total number of cookies that Mary and Natalie have the same. LCM of 4 and 7 is 28.
Total number of cookies that Mary and Natalie have
= 21 u + 7 u
= 28 u
Number of more cookies that Mary and Natalie have than Sarah
= 28 u - 4 u
= 24 u
24 u = 288
1 u = 288 ÷ 24 = 12
Number of more cookies that Mary has than Natalie
= 21 u - 7 u
= 14 u
= 14 x 12
= 168
Answer(s): 168
