642/1,100 is equivalent to approximately 58.4%, therefore you can find what 58.4% of 40,000 is. In this case, it would be 23,360 people.
You can also divide 40,000 by 1,100 to find the amount it is increased by, which is 36.4. Then, you can multiply 642 by 36.4 to get a more accurate answer of 23,368.8 people.
Explanation: These type of questions can easily be solved using the Venn diagram. Below is the image attached that shows the Venn diagram and the solution.
They make 18 chicken burritos because when you do 24 beef burritos total divided by 4 beef burritos you get 6 beef then you muliply 6 by the number of chicken burrittos.