Answer:
The probability is 63/1000 or 0.063
Step-by-step explanation:
Here, given that she takes 3 coins , we want to calculate the probability that the sum is £2.50
What we simply have to do here is to get the different ways to arrange £2.50 within 3 selections ONLY
we can only have this as;
taking 2 £1 coins and 1 50 pence coins
The probability of taking a £1 coin is 3/10
The probability of taking a 50 pence coin is 7/10
So the probability of 2 £1 coins and 1 50 pence coins will be;
3/10 * 3/10 * 7/10 = 63/1000