Question 1123425
It would take one man  (3.5hrs) * 5 = 17.5 hrs 

So 7 men, working at the same rate, can do the job in  17.5hrs/7 = {{{ highlight( matrix(1,4, "","2.5",""," hrs")) }}}<br>

To find the number of seconds, multiply 2.5hrs x (3600 sec/hr).  You can do that calculation.