Fiza has 10 coins in a bag there are three £1 coins and seven are 50 pence coins
fiza takes at random, 3 coins from the bag
work out the probability that she takes exactly £2.50

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

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