How many seconds will a boy take to run one complete round around a square field of side 38 metres, if he runs at a speed of 6km/h ?

Correct option is D

Given:

Side of a square field = 38 meters

The speed of boy = 6 km/hr

Concept used:

To convert kilometers per hour to meters per second, multiply it with  $$\frac{5}{18}$$​​

Formula used:

Perimeter of square = 4 × side of square

​$$Time(T)=\frac{Distance(D)}{Speed(S)}$$   

​Solution:​

We will covert its unit with m/s, so we get 6 km/hr =$$\frac{6×5}{18} =\frac{5}{3}m/s$$​​

According to the question:

Distance run around the field (D) = Perimeter of the field

Perimeter of square = 4 × side of square

=> D = 4 × 38m = 152 meter

=>T= $$\frac{152×3}{5}sec =$$​  91.2 sec

∴ Time taken to run around the field is"91.2" sec.