Matt and Ruba each have one coin.
The total amount of money is less than 50p.
Work out the probability that exactly one of the coins is a 10p piece.
Assume that all possible coins are likely.
By "p" do you mean pence? Because if so than could you list the denominations?
If it's UK coins then the denominations less than 50p are:
1p; 2p; 5p; 10p; 20p