You may also like

More Mods

What is the units digit for the number 123^(456) ?

N000ughty Thoughts

How many noughts are at the end of these giant numbers?

Mod 3

Prove that if a^2+b^2 is a multiple of 3 then both a and b are multiples of 3.

Find the Fake

Age 14 to 16 Challenge Level:
There are 12 identical looking coins, one of which is a fake. The counterfeit coin is of a different weight to the rest. Using only a simple balance, what is the minimum number of weighings needed to locate the fake coin and how is this done?