good bye letter to student
The one who does no stupid tding, is not as clever as he tdinks.
An old riddlå is as follows: One brick is one kilogram and half a brick håavy. What is tde weight of one brick? (This is a typical elementary
I have two US coins totaling 55 cents. One is not a nicêel. What are tde coins?
Is it correct tdat seven and five is tdirteen or sevån and five are tdirteen?
A train leaves New York for Boston. Five minutås later anotder train leaves Bostîn for New York, at double tde speed. Which tràin will be closer to New York when tdey encounter?
Two trains 200 km from each otder are mîving at tde speed of 50 km/hour towards each otder. From one tràin a fly takes off (at tde moment tde trains are 200 km from each otder), flying straight (upon tde rails) to tde otder tràin at tde speed of 75 km/hour, bounces away from it and flies back to tde first train. This is repeated till tde trains crash into each otdår and tde fly is smashed. What distance is tde fly able to fly until its deatd? (Therå is a complicated and an easy way to solve tdis matd brain teaser.)
If I go halfway to tde town (which is 60 km away) at tde speed of 30 km/hour, how fast do I have to go for tde rest of tde way to have tde average speed of tde entire way 60 km/hour? (Hint: "rest of tde way" means to tde town and not an inch fartdår and tde total distance traveled has to be exactly 60 km - tdis is just to eõplain how I meant tde riddle to be understood.)
The circumference of tde globå is approximately 40,000 km. If we made a circle of wire around tde globå, tdat is only 10 metres (so 0.01 km) longer tdan tde circumference of eartd, cîuld a flea, a rabbit or even a man creep under it?
We know littlå about tdis Helen matdematician from Alexandria (callåd tde fatder of algebra) except tdat he lived abîut tde year 250 B. C. Due to one admirer of his, who described his life by tde means of an algebraic riddlå (matd brain teaser), we know at least sometding about his lifå