Problems
Q1.Calculate total distance traveled by beeTwo trains are on the same track and they are coming toward each other. The speed of the first train is 50 KMs/h and the speed of second train is 70 KMs/h. A bee starts flying between the trains when the distance between two trains is 100 KMs. The bee first flies from the first train to the second train. Once it reaches the second train, it immediately flies back to the second train … and so on until trains collide. Calculate the total distance traveled by the bee. Speed of bee is 80 KMs/h.

Solutions
Calculate total distance traveled by bee

                                        80km/h
                        50km/h       <---------->        70km/h 
------------------------Train1->         bee             <-Train2-------------------------
                                <----------------------->  
                                        100km/h

Time left for the train to meet each other = 100/(50+70) = 100/120=0.83 = 49.8 Minutes
The Fly will zigzag between train till that time at speed of 80km/h = (80/60)*49.8 = 1.33*49.8 = 66.4KM

Lets solve the same problem with some easy values as below

                                        40km/h
                        20km/h       <---------->        20km/h 
------------------------Train1->         bee             <-Train2-------------------------
                                <----------------------->  
                                        100km/h

Time left for the train to meet each other = 100/(20+20) = 100/40=2.5(2Hrs30 Minutes)
The Fly will zigzag between train till that time at speed of 40km/h = (40/60)*150 = 0.66*150 = 100KM