 Hi and welcome to the session. Let us discuss the following question, question size. Find the values of the letters in each of the following and give reasons for steps involved. Let us now start with the solution. Now let us rewrite the given person. That is 2ab plus 1 gives b18. Now we need to find the value of 2 letters that is a and b. Now observe the addition in one's column. Clearly you can see units place of b plus 1 is 8 or you can say once place of b plus 1 is 8. Now this happens only if value of b is 7. If we substitute 7 for letter b in this given person then we get 2a7 plus a71 gives 718. Now observe the addition in 10's column. Clearly you can see once place of a plus b is 1. Now for b is equal to 7 a plus b is 1 in 10's column only if value of a is 4. Now if we substitute 4 for a and 7 for b in this given puzzle we get 247 plus 471 gives 718. Now clearly you can see 247 plus 471 is 718. 7 plus 1 is 8 once place of 4 plus 7 is 1 and 10's place of 4 plus 7 is also 1. So 1 is carry in 100's column. So adding 1, 2 and 4 we get 7. So value of a and b are 4 and 7. So here we have solved the given puzzle and these are the required values of a and b. This completes the session. Hope you understood the solution. Take care and bye for now.