Kia has 10 coins in a bag. There are three £1 coins and seven 50 pence coins.
Kia takes at random, 3 coins from the bag.
Work out the probability that she takes exactly £2.50

In a survey of 1015 adults, a polling agency asked, "when you retire, do you think you will have enough money to live comfortably or not. of the 1015 surveyed, 534 stated that they were worried about having enough money to live comfortably in retirement. construct a 90% confidence interval for the proportion of adults who are worried about having enough money to live comfortably in retirement.