I am a 4 digit number all my digits are different they add up to 20 the hundred's digit is double than the one's digit

- 2864

Step-by-step explanation:

Given that,

The number is of 4 digits

All are different

The sum of the 4 digits = 20

Hundred's digit is twice than one's digit

A.T.Q.

Let the unit digit be 4. So, the hundred's digit would be 4 * 2 = 8

Now, we have

_8_4

We know that the sum of four digits is 20. Thus,

_ + 8 + _ + 4 = 20

∵ _ + _ = 20 - 12 = 8

The possible numbers must make a sum of 8. Thus, one possibility can be 2 and 6.

Therefore, the number can be

2864  

( 2 + 8 + 6 + 4 = 20)