Mr. mcgregor hires adam, samantha, and gary to byild a fence around his yard. it takes adam 4 hours to build a fence along the right side of the yard. it takes gary 6 hours to build a fence along the left side of the yard. it takes samantha three hours to build a fence along the back of the yard. assuming that all the sides of the yard are equal in lenth, how long will it take adam, samantha, and gary to build a fence along the front side of the yard if they work together and do not interfere with each other's work