Problema Solution
One secretary can do a particular typing job in 6hr and another secretary can do the same job in 4hr. How long will it take if the job is done by the two secretaries working together?
Answer provided by our tutors
let
x = the hours the two secretaries need to finish the job together thus their rate is 1/x job per hour
the rate of the first secretary (1/6 job per hour) + the rate of the second secretary (1/4 job per hour) = together rate 1/x job per hour
1/6 + 1/4 = 1/x
by solving we find
x = 2.4 hr
x = 2 hr 24 min
click here to see the step by step solution of the equation
the two secretaries together will finish the job in 2 hours and 40 minutes.