The formula would be m = x/n. We can then determine that there are 15 rows.
To find the equation, we simply have to know that multiplying the rows by chairs gives us the total number of people (mn = x). Then we can solve for m by dividing both sides by n. (m = x/n)
Net we need to find the number of rows. To do so we'll look at the formula we created. We know that there are 60 people, which is our x value. We also know there are 4 chairs in a row, which is our m value. We need to find n
m = x/n ---> plug in
4 = 60/n ---> cross multiply
4n = 60 ----> divide by 4
n = 15
