Question

There is an unknown number •it is a four digit number •the tens are double the ones •the thousands are double the tens •the sum of the digits of nineteen

Answer 1

Answer:

8542

Statement

1.It is a four digit number

2.The tens are double the ones

3.The thousands are double the tens

4.The sum of the digits is nineteen

Step-by-step explanation:

It is a four digit number

lets take 4 digit number-ABCD

The tens are double the ones

$C=2D$-----------------------------1

The thousands are double the tens

$A=2C$-------------------------------2

According to equation 1 and 2

$A=4D$

If we take

$D=1,2$

Possible number

$4B21$ OR $8B42$

The sum of the digits is nineteen

I use hit and trial method

$4B21$- If I take B is maximum

$4+9+2+1\neq 19$

$8B42$- If, i try to find value of B

$8+B+4+2=19$---------------------3

$14+B=19\\B=19-14\\B=5$

So the unknown number is-  8542