In this task, you need to provide the correct option for a given problem from the provided options.

Problem: one fast typist type some matter in 4 hrs and another slow typist type the same matter in 6 hrs . if both do combine in how much time they will take to finish . 
Options: a ) 10 hr , b ) 1 hr , c ) 2 hr 24 mins , d ) 3 hr 4 mins , e ) 4 hr 10 mins
c