Question

A three digit number 7a2 is added to another 3 digit number 685

Answer 1

A three digit number 7a2 is added to another 3 digit number 685  We can add further to the question as to give a four digit number 13b7 divisible by 11

Consider the number 7a2 and 685  

Let us first try the numbers for 13b7 from 0 to 9

It can be 1307, 1317, 1327, 1337, 1347, 1357,..........1397 and so on

Now by adding the numbers we get 7a2 + 685 = 13b7

The only number divisible by 11 is 1397. So we can put

7a2 + 685 = 1397.  

712 + 685 = 1397

Obviously a is 1 and b is 9

Answer 2

Answer:

a =1

b  = 9

Step-by-step explanation:

The question is not complete. The complete question is as follows:

A three digit number 7a2 is added to another 3 digit number 685 to give a four digit number 13b7 divisible by 11.

Now, our given numbers are

First Number = 7a2

Second Number = 685

Result of Adding first two numbers = 13b7

Now, we are given that 13b7 is divisible by 11. If we try all the numbers from 0 to 9 for b we find that it is possible only if we take b =9. So,

Our Desired Number = 1397

Let us now find the number a

as per given condition

7a2 + 685 = 1397

So,

7a2 = 1397 - 685

7a2 = 712

So, now by comparison we can see that a is equal to 1.