Question

A file of cadets consisting of ten rows and five columns measures 420
m in length along the direction of their marching. How much time (in hours and
minutes) would it take to march for a stretch of 3 km, if the stride of each cadet is
80 cm and he takes 57 strides per minute?

Answer 1

Answer:

      1 hr 15 min

 Explanation:

      So total distance need to be covered by last cadet

=> D = 420

Speed =  [(80/100) * 57 * (1/60)] per sec

            =  76/100 m/sec

Now

T=D/S

T= (3420 x 100) /76 = 4500 sec

= 75 min = 1 hr 15 min