How do you work this things out ! (1 Viewer)

[Vittorio15]

Hey guys , i can never get the hang of doing this stuff can someone please try explain it to me ..... Three-digit numbers are formed from five cards labelled 1, 2, 3, 4 and 5 How many different three-digit numbers can be formed?

 

[hazza9]

Yea I’m not great at them either. If I had to have a best guess I would say: 5 x 4 x 3 = 60. This is because: On the first card it could be five numbers, On the second card it could be four numbers, On the third card it could be three numbers. Not sure if this is right but hope it helps

 

[ONoezzz]

Just seconding the previous poster...and he/she beat me to it!

This is an Ordered Selection question from Probability.
There are 5 cards, and you cannot repeat each card to arrange the 3-digit number. The 1st digit can have one of either 5 cards/possibilities, the 2nd digit can have either 4 cards/possibilities (as one of the cards was taken into the first digit already) and the 3rd digit can have either 3 cards/possibilities (as two of the cards was taken into the first two digits already)
Therefore to work out this question you go: 5 x 4 x 3 = ... different three-digit numbers can be formed.

Hope this helps!