How quickly will money double if it is invested at an annual interest rate of 3% compounded continuously

To find this answer you will need to convert the number of miles to feet.  1/4 mile = 1320 feet long.  Now consider how many groups of 5 you can make out of this.

1320/5 = 264 sections that are 5 feet deep and 5 feet wide.

Each of these 5 x 5 sections will hold approximately 10 people, so 264 x 10 = 2640 people.

There are approximately 2640 people in the crowd.