Question

Mukesh walks around a circular track of radius 14 m with a speed of 4 km/hr. If he takes 20 rounds of the track, for how long does he walk?

Answer 1

Radius of the circular track = 14 m

Circumference of the circular track = 2πr

= ${\displaystyle 2\times \frac{22}{7}\times 14}$

= 44 × 2

= 88 m

Total distance cover in 20 rounds = 88 × 20 = 1760 m

Speed of Mukesh on the circular track = 4 km/h

= ${\displaystyle \frac{4\times 1000}{60}}$

= ${\displaystyle \frac{2\times 100}{3}}$

= ${\displaystyle \frac{200}{3}}$ m/min

Time taken by Mukesh = ${\displaystyle \frac{1760}{\frac{200}{3}}}$

= ${\displaystyle \frac{1760\times 3}{200}}$

= ${\displaystyle \frac{176\times 3}{20}}$

= 26.4 min

26.4 min = 26 min and 24 s