Question

Kill’em Dead Pest Control needs to set out 5 roach motels per square yard. In a rectangular studio apartment that’s 7 yards by 4 yards wide, about how many roach motels will need to be set out?

Answer 1

5 roach motels per square yd

A = L * W
A = 7 * 4
A = 21 square yds

so if they set out 5 roach motels per square yd, then they need to set out :
5 * 21 = 105 roach motels <==