Question

Using all the one-digit prime numbers each one Li one how many four-digit odd numbers greater than 3000 can be formed?​

Answer 1

Step-by-step explanation:

find the simplest form of fraction 30 upon 75

Answer 2

Step-by-step answer:

The one-digit prime numbers are: 2, 3, 5, 7.

Since we need numbers greater than 3000, 2 can never be the thousand's place digit, meaning we have 3 possibilities for the thousand's place digit.

_3_ __ __ __

Now we know that the number has to be odd at all times, meaning there are only two possibilities for the unit's place digit, since 2 in unit's place will make the number even and the remaining digits are required for the number to be greater than 3000.

_3_ __ __ _2_

Going forward, we only have 2 digits left to fill and 2 numbers left, meaning we can simply have 2 possibilities for hundred's place digit and 1 remaining possibility for ten's place digit or vice-versa, however you like.

_3_ _2_ _1_ _2_   OR  _3_ _1_ _2_ _2_

This means we have a total of ( 3 x 2 x 1 x 2 ) = 12 numbers that can be formed using prime numbers that are greater than 3000.

Verification:

The numbers are:

3257, 3275, 3527, 3725,

5237, 5273, 5327, 5723,

7253, 7235, 7325, 7523

Answer: 12 numbers

I hope this helps. :D [ It's been a long time. ;) ]