Two trains set off at the same time from each end of a single
straight railway line. A very fast bee starts off in front of the
first train and flies continuously back and forth between the two
trains. How far does Sidney fly before he is squashed between the
If it takes four men one day to build a wall, how long does it take
60,000 men to build a similar wall?
Which segment on a digital clock is lit most each day? Which
segment is lit least? Does it make any difference if it is set to
12 hours or 24 hours?
John, Peter, Rudolf, Susie and Tony decide to set some questions for the Schools Mathematical Challenge.
John thinks up twenty-five questions and circulates them to the others. Peter, not wishing to be outdone, then sends twenty-six questions. Rudolf decides he had better get cracking and produces thirty questions. Susie sets to and comes up with thirty-nine posers, only to be beaten by Tony who produces fifty five stunning problems.
If each person takes half as long as the previous person to set each question, and Rudolf takes one hour to set all his questions, then what is the total time spent settting questions?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
This problem is taken from the UKMT Mathematical Challenges.