00:01
So, in the given question we are told that 7 times a 2 digit number, 7 times a 2 digit number, a 2 digit number is equal to 4 times the number is equal to 4 times the number, 4 times the number obtained by reversing the order of digits obtained by obtained by reversing the order of digits reversing the order of digits and now we're also told in the question if the sum of the digits of this number the sum of the digits of the number digits of the number of the number is equal to nine so these are the things that are given in the question and we are told to find the number that is being mentioned over here the two -digit number that is mentioned so what do we do we can write let the 2 digit number be, let the 2 digit number be, digit number b, 10x plus y.
01:47
So why do we take the 2 digit number in this form? first, let's look at an example so that you can understand.
01:55
Let's say, let's take the number 17, right? so in the number 17 we can write this number 17 as 10 times 1 plus 7 plus 1 times 7.
02:12
Now the reason why we can write it like this is because we call the place where 7 is now as the 1's place and the place of 1 is the 10's place.
02:25
So this means we can write the number as 10 times 1 plus 1 times 7.
02:36
So this would then be equal to 10 plus 7 which is equal to 17.
02:43
So the digits over here are 1 and 7.
02:48
So we multiplied the place values with the digit and we got the number.
02:55
This is the same thing that we are going to do with the number that we have with us also because the digits, the digits of this number are x and y, x and y and they form the two digit number 10x plus y, right? where x is having the 10's place and y is having the 1's place...