Mary has 20 biscuits in a tin. There are: 11 plain biscuits. 7 chocolate biscuits. 2 currant biscuits. Sue takes at random two biscuits from the tin. Work out the probability that the two biscuits were not the same type. HELP ASAP!!

70 points ! pls 2. given the following two sets of data what is the union of the two sets and what is the intersection of the two sets. set a = {1, 2, 3, 4, 5, 6, 7, 8, 9} set b = {2, 4, 6, 8, 10, 12, 14} 3. given a regular deck of cards. describe a way of pulling cards that would create a dependent event and then one that would create an independent event. 4. what is the probability of drawing a red card and then drawing a spade without replacing the card that was drawn first?