Cheryl finds a bag of coins. There are 50 coins inside and the value of the contents is £1.81. Given that it contains only two-pence and five-pence coins, how many more five-pence coins are there inside the bag than two-pence coins?
If you liked this problem, here is an NRICH task
that challenges you to use similar mathematical ideas.
This problem is taken from the UKMT Mathematical Challenges.