MAN1 is 30% more efficient than MAN2. How much time will they, working together, take to complete a job which MAN1 alone could have done in 23 days?  Select:  A) 10 days  B) 12 days  C) 13 days  D) 14 days  E) 15 days
Man1 and Man2 = 100:130 = 10:13   ==&gt; Man2 ==&gt; x days   then 10:13:23 :x ==&gt; x=(23*13/10)   x=299/10   Man 1 day work = 1/23   Man2 work = 10/299   (A+B) = 1/23+10/299 = 1/13   ==&gt;13 days   ANSWER 13 days
<result>C</result>
MAN1 is 30% more efficient than MAN2. How much time will they, working together, take to complete a job which MAN1 alone could have done in 23 days?