Answers to the Age Maths Challenge 2009

Below are the quick answers to our 2009 AGE Maths Challenge. Click here to download the answers in pdf format.

We've also prepared detailed solutions for you, which you can download here: Easy (1 point), Medium (2 points), and Hard (3 points).

And, if you're looking for more puzzles to while away the time until Christmas, you can check out the 2008 Challenge here and here, with solutions here.

E1: Yes.
E2: Four coins.
E3: 6.
E4: A maximum of 8 and 16 different notes (fewer for most real trumpets).
E5: 190 handshakes.
E6: 5550001 or 5552802.
E7: Ten times.
E8: 0 or 2/5.
E9: Archimedes, Penrose, Fermat, Zeno, Euclid.
E10: 37.

M1: Cut the pizzas in half, but five pieces is the minimum.
M2: The same (roughly).
M3: The first player can force a win.
M4: It doesn't matter.
M5: 3²¹.
M6: The rings have the same area.
M7: Alphabetical order.
M8: The area is 1/4.
M9: A circle, and ellipses.
M10: 2 or 4, or neither.

H1: 42 meters (Vale, Douglas Adams).
H2: Six ways in total.
H3: Six shuffles.
H4: Yes.
H5: Yes, you should switch.
H6: Yes, the path is possible.
H7: Yes, there are enough boxes.
H8: We let you choose first.
H9: There is zero area left, but infinitely many points.
H10: 7/4.