Question

A four- digit number ( with no repetitions) is to be formed from the set of number ( 0,1,2,3,4,5,6,7). Find the probability that the number :

a) is even

Answer 1

You first find the number of four-digit numbers that may be formed from the above set.

Answer 2

Think of it this way, pick the numbers from right to left, least significant first.

Answer 3

Can you do that? \[8P4 \] But there is something—we can't place a zero.

Answer 4

the probability is 50 %

Answer 5

i did
6x6x5x4
-------
7x7x6x5 ?

Answer 6

Let's think of slots.
_ _ _ _
Four slots.

We have 7 choices for the first(there are eight numbers in the set, but we can't place a zero).

7 for the second too(we have a zero with us the second time).

6 for the third. (We already have two numbers filled out of eight).

5 for the fourth. (We have three filled).

Answer 7

We multiply \(7 \times 7 \times 6 \times 5 \Longrightarrow 49 \times 30 \)

Answer 8

yes then? number of even numbers = 6x6x5x4 i that correct

Answer 9

First find the number of four digit numbers you could make, then divide that by 2.

Answer 10

um answer is not 1/2 though

Answer 11

every number that ends with a 0,2,4 and 6 is an even number, so if 4 out of 8 digits give you an even number wouldn't that be 50/50?

Answer 12

@ParthKohli see my post above. Make sense?

Answer 13

Yup! That's correct!

Answer 14

@ParthKohli answer is given as 780/1470 not 735/1470?