It will take 1.5 hours for 16 men to dig a trench 48 m long.
It should be noted that the time needed is direct proportional to the length of the trench, and inverse proportional to number of men.
The equation can be written as
t=kl/m..................................................... eqn(1)
Then if we substitute the given figures we have,
3=90k/15
Then k= 0.5
then substitute into eqn(1) we have
t=0.5 l/m
Therefore, since 16 men, 48m long, is required, the time will now be calculated as :
t=0.5 48/16
t= 1.5 hrs.
Therefore, It will take 1.5 hours for 16 men to dig a trench 48 m long.
Learn more about proportionality on:
https://brainly.com/question/21749206
#SPJ4
