 Hello and welcome to the session. In this session we discussed the folly question that says the difference between a two digit number and the number obtained by interchanging the positions of its digits is 36. What is the difference between the two digits of that number? Before moving on to the solution, let's recall the formation of a number with two digits a and b, a in the tens place and b in the units place. This is equal to 10 into a plus b. This is the key idea for this question. Let's move on to the solution. We first assume let the units digit of a two digit number be equal to x and let the tens digit of a two digit number be equal to y. So the number formed is equal to 10 into the tens digit that is y plus the units digit that is x. Now the number formed by interchanging the digits would be equal to 10 into x plus y that is 10 x plus y. Now according to the question we have that the difference between a two digit number and the number obtained by interchanging its digit is 36 that is we have 10 y plus x minus 10 x plus y is equal to 36. Here we have subtracted the number obtained by interchanging the digits from the original number. We can also subtract the original number from the number obtained by interchanging its digit that is we can also have 10 x plus y minus 10 y plus x is equal to 36. Now this would be further equal to 10 y plus x minus 10 x minus y is equal to 36 that is 9 y minus 9 x is equal to 36. From here we get y minus x is equal to 4. In this case also we have 10 x plus y minus 10 y minus x is equal to 36 that is 9 x minus 9 y equal to 36 this gives us x minus y is equal to 4. So the difference between the two digits of the number is equal to 4. Now here we have the units digit is subtracted from the 10th digit and in this case we get the 10th digit is subtracted from the unit digit. So final answer is 4. This completes the session. Hope you have understood the solution for this question.