Question

Mr Ernst leaves home at noon, traveling at 50 mph. His loving wife leaves at 1 pm with a briefcase that Mr. Ernst forgot. How fast must his wife drive to catch him by 5 pm?

Answer 1

d1 = 50mi/h * 1h + 50mi/h * 4h = 250 mi

d2 = r*t = 250 mi
r*4 = 250
r = 62.5 mi/h = Wife's speed.