A cyclist travels
A cyclist travels the length of a bike path that is 225 miles long, rounded to the nearest mile. If the trip took him 5 hrs, rounded to the nearest hour, then his average speed must be between:
A. 38 and 50 mph
B. 40 and 50 mph
C. 40 and 51 mph
D. 41 and 50 mph
E. 41 and 51 mph
My Ques: How do we do the approximation and define the range?
If the distance is 225 miles rounded to the nearest mile, the range for the distance is 224.5 < = Distance < = 225.5.
Similarly since the time is 5 hours rounded to the nearest hour, the range for the time is 4.5 < = Time < = 5.5.
So to get the range we just need to find the extreme values.
224.5/5.5 will be the lowest possible speed since we are considering the lowest numerator and the highest denominator. = 40.8
225.5/4.5 will be the greatest possible speed since we are considering the highest numerator and the lowest denominator = 50.1
So the range here has to be between 40 and 51.