Question

1.What is the value of X so that the seven digit number 8439X53 is divisible by 99?
Given Ans: a)9 b)4 c)3 d)6

What I did is,
11*9=99
8+4+3+9+5+3=32
So, lets add given numbers one by one to check if that number is divisible by 9.
32+9=41(41 not divisible by 9)
32+4=36(is divisible by 9)
So 4 is the correct answers.

■Now, Question is, When I am trying to solve a same type of question. All the result are coming not divisible. How is this possible and why its happening?

2, What is the value of X so that the seven digit number 6913X08 is divisible by 88?
Given Ans: a)4 b)2 c)8 d)6

So lets first sum the total numbers. its 27.
11×8=88
So,
27+4=31(Not divisible by 8)
27+2=29(Not divisible by 8)
27+8=35(Not divisible by 8)
27+6=33(Not divisible by 8)

Why its not working? any genius of mathematics?
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Answer 1

Answer a) 4

b) 3

these are the correct answers

Answer 2

Answer:

1.What is the value of x so that the seven digit number 8439x53 is divisible by 99? 8439x53 will be divisible by 99 if it is divisible by both 9 and 11. If x= 4 , then sum would be 36, satisfying the rule for 9. So , the answer would be option b)4