Question

Jess observed that 60% of the people at a mall on a particular day shopped for clothes. If 2500 people at the mall did not shop for clothes that day, the number of people who shopped for clothes that day was ______. (only put numeric values, no other symbols)

Answer 1

If 60% did not, then 40% did

Set up a proportion.
60%/ 2500 = 40%/x
60% x = 2500 * 40%
x = (40% / 60%) * 2500
x = (0.4 / 0.6) * 2500
x = 1666.667
You have to round this, but which way? I would go down.

You could do this another way. Find 100% first.
60% of x = 2500
x = 2500 / 0.6
x = 4166.666666

That is the total number of people he saw.
Take out the 2500
4166.66666 - 2500 = 1666.6666
You arrive at the same place. Which do you like better?