The answer is the 3rd option: 234. Let me explain this to you like this: There are 3 remainders and they are 3 digit numbers so it is evident that the divisor is also 3 digit number. So what you need to do is
643-175=468
Then:
1752-114=1638
Then
1149-213=936
Please notice that numbers 468 ,1638 ,936 are exactly divisible by the same divisor. So find the Greatest Common Denominator of the above 3 numbers which comes out to be 234. And that is the trick. Hope this helps
