If a man travels p hours at an average rate of q miles per hour, and then r hours at an average rate of s miles per hour, what is his overall average rate of speed?
সমাধান
সঠিক উত্তর: Option A
Total miles traveled in p hours = p x q miles and
Total miles traveled in r hours = r x s miles
so, average rate of speed = total miles traveled / number of hours
=[{(p x q)+(r x s)} / (p+r)]= (pq+rs)/(p+r)miles per hour
