AboutRohit Agarwal Expertise I can answer questions related to numbers and logic easily. However I sometimes face problems when solving questions that require a lot of creative thinking. I am not good at puzzles which involve a play with words, so please don't ask me to solve such puzzles for you.
Experience I have read a couple of good books containing puzzles and can now claim to have an "expert" in this field. I have been invited to become a member of Mensa.
Organizations INDIAN INSTITUTE OF TECHNOLOGY, DELHI
Education/Credentials Currently doing Dual Degree (B.Tech M.Tech) in Electrical Engineering Department from INDIAN INSTITUTE OF TECHNOLOGY, DELHI
Awards and Honors Numerous certificates recognizing my ability in Mathematics and Logical Thinking
Question hello, my name is Jennifer and i would like to check the answer to this question:
Two trains 200 km from each other are moving at the speed of 50 km/hour directly towards each other. From one train a fly takes off (at the moment the trains are 200 km from each other), flying straight (along the rails) to the other train at the speed of 75 km/hour, bounces away from it and flies back to the first train. This is repeated until the trains crash into each other and the fly is smashed.
What distance is the fly able to fly until its death?
Answer This is a very good question and there are two approaches to answer it. The obvious approach is difficult and involves an infinite summation. The other approach is quite lucid and is as follows.
From the moment the fly takes off for the first time to the moment the trains collide, the fly flies constantly and at the same speed of 75 kph. It takes the trains 200/(50+50) = 2 hours to collide. Hence the total distance flown by the fly is 75 * 2 = 150 km.
