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Urgent maths help!!!

Can someone please help me with this question - my exam is tomorrow!!

Marie has 25 cards.
Each card has a different symbol on it.
Marie gives one card to Shelley and one card to Pauline.
(a) In how many different ways can Marie do this?

Reply 1

Westsidegirl

The mark scheme say the answer is 600 - the working out is 25x24 but i do not understand why??

1/25 * 1/24=600

cause she picks one card thus it is 1/25 and then after she give that card that card is now removed from the total number of cards she has. This will mean it is 1/24 now

Reply 4

Westsidegirl

Original post by sd23123

cause she picks one card thus it is 1/25 and then after she gives that card that card is now removed from the total number of cards she has. This will mean it is 1/24 now

Sorry to ask I again but I still do not understand why do you not multiply 1/25 by 1/24, why is it 25x24.

Reply 5

-Phoenix-

Original post by Westsidegirl

Sorry to ask I again but I still do not understand why do you not multiply 1/25 by 1/24, why is it 25x24.

The way I would go about doing this is:
Marie can choose from 25 cards. Then, since one card is taken out, there are only 24 left for Pauline to choose from. Therefore, you can have 25*24 different combinations. When one card is picked, it can pair with 24 others. You can do this 25 times, so it's 25*24=600