If all the faces of a tetrahedron have the same perimeter then show that they are all congruent.
A group of 20 people pay a total of £20 to see an exhibition. The admission price is £3 for men, £2 for women and 50p for children. How many men, women and children are there in the group?
I am exactly n times my daughter's age. In m years I shall be exactly (n-1) times her age. In m2 years I shall be exactly (n-2) times her age. After that I shall never again be an exact multiple of her age. Ages, n and m are all whole numbers. How old am I? Now suppose there is some wishful thinking in the above assertion and I have to admit to being older, and indeed that I will be an exact multiple of her age in m3 years. How old does this make me?
There were lots of approximate solutions here coming so close that the hands would appear to swop over. The closest were Selina Tang from The International School, Brunei who suggested that the train left at 6.47 and arrived at 9.34 taking 2 hours 47 minutes and Kang Hong Joo, The Chinese High School, Singapore, who suggested 2 hours 46 minutes but admitted to
being unable to explain why. If you know that it leaves between 6.47 and 6.48 and arrives between 9.33 and 9.34 can you get closer to the exact times?