 Hello and welcome to the session. The given question says, the sum of the digits of a two-digit number is 12. The number obtained by interchanging the two-digit exceeds the given number by 18. Find the number. Let's start with the solution and let the digit at the unit's place of the required number, the digit at the 10th place of the required number be, therefore, required number is given by 10 into y plus x, since y is in the 10th place and x is in the unit's place, so we multiply y by 10 and x by 1. Now the question further says, the number obtained by interchanging the two digits exceeds the given number by 18. Interchanging the digits of the number which are x and y, the new number is, now on interchanging the digits place, so we have multiplied it by 10 and y comes on the unit's place, so we have multiplied it by 1. So this is the new number which we have obtained by interchanging the digits x and y. Now the question says, the number obtained by interchanging the two digits exceeds the given number, the new number which is 10x plus y is greater than the required number which is 10y plus this be equation number 1. So we are given that the sum of digits of a two-digit number is 12, therefore this is the equation number 2. Here x and y are the digits of two-digit number. Now on subtracting the second equation from the first equation we have minus, minus and here also minus, cancelling the right terms with opposite sign we have minus 2y is equal to minus 10. Now substituting 25, in equation number 1 we have x minus 5 is equal to 2 or x is equal to, therefore we have y is equal to the required number which is equal to 10y plus x is equal to 10. Two-digit number is shouldn't buy and take care.