Question

Ahmed competed in a competition that has a walking part and a biking part. The entire course was 15 miles. On average, Ahmed walks 3 mi/hr and bikes 12 mi/hr. Of the walking part of the competition took 1 hour longer than the biking part, how long did it take Ahmed to complete each part of the competition?

Answer 1

Walking part: 1hr 48mins

Biking part: 48 mins

Explanation:

Total distance covered = 15 miles

Let the time taken for walking = w hours

Let the time taken for biking = b hours

Walking part took one hour longer than the biking part.

So, w = b + 1

// Distance covered, d1 = Speed * time taken

For walking part, d1 = 3 * w = 3w

But w = b + 1

So, d1 = 3(b + 1) = 3b + 3 miles

For biking part, d2 = 12 * b = 12b

d1 + d2 = Total distance covered

3b + 3 + 12b = 15

3b + 12b = 15 - 3

15b = 12

Divide both sides by 15

15b/15 = 12/15

b = 0.8 hour

But, w = b + 1

So, w = 0.8 + 1 = 1.8 hours

Ahmed took 0.8 hour (0.8 * 60min = 48mins) to complete the biking part and 1.8 hours (1hr + 48mins = 1hr 48mins) to complete the walking part