I have a tin of chocolates to share with some friends. In the tin are four types of chocolate – one type in red wrappers, one type in blue, one type in green and one type in yellow, with equal numbers of each.
The tin is passed around in turn from friend to friend. When the tin gets to them:
• John always takes three red chocolates.
• Peter always takes one of each colour.
• Jane always takes one yellow chocolate.
• I always take two green chocolates.
After six passings around of the tin, half of the chocolates remaining in the tin are blue.
How many chocolates were there in the tin when it was full?