Question

I am thinking of a 4-digit number. The digit in the thousands place is twice the digit in the tens place. The digit in the tens place is 1 more than the digit in ones place. The digit in the ones place is 1. If the sum of the digit is 13. Find the number.

Answer 1

Answer:

3912

Step-by-step explanation:

according to the question the number should be 3xy2

where x and y are the unknown digits.

upon expanding it, and according to the given condition in the question;

(3*1000+x*100+y*10+2)-(3*1000+y*100+x*10+2)=720

100x+10y-100y-10x=720

90x-90y=720

x-y=8

by hit trial method; we find that

x=9

y=1

therefore number=3912