Question

Sum of digits of 2 digit no is 7
When we interchange the digits the resulting number smaller than the original number by 45 .find the original number.

Easy qs !! I wanna see who can do it for 20 points post only irrelevant ans​

Answer 1

Let the original number be yx ;

i.e., 10y+x. We know x+y=7. The number obtained by reversing the digits in xy , i.e., 10x+y. The second condition gives 10x+y−2=2(10y+x). Thus we have two equations:x+y=7....(1)8x−19y=2....(2)Multiply the equation (1) by 19 and get19x+19y=133.Adding this to (2), we obtain 27x=135. This gives x=5. Hence y=7−x=7−5=2.

The required number is 25.