Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 37)
37.
A 3-digit number 4a3 is added to another 3-digit number 984 to give a 4-digit number 13b7, which is divisible by 11. Then, (a + b) = ?
Answer: Option
Explanation:
4 a 3 | 9 8 4 } ==> a + 8 = b ==> b - a = 8 13 b 7 |
Also, 13 b7 is divisible by 11 
(7 + 3) - (b + 1) = (9 - b)
(9 - b) = 0
b = 9
(b = 9 and a = 1) (a + b) = 10.
Discussion:
35 comments Page 4 of 4.
Neelu said:
1 decade ago
I could not understand this problem.
i.e. How we got (7+3) - (b+1) from 13b7 ?
i.e. How we got (7+3) - (b+1) from 13b7 ?
Kiran said:
1 decade ago
Soma-->
the number is divisible by 11 if the difference between the sum of its digit at odd places and the sum of its digit at even places is either 0 or number divisible by 11.
4 a 3 | ==> here a can either be 0 or 1
9 8 4 }
13 b 7 |==> so b can be either 8 or 9
but (7+3) - (b+1) should be divisible by 11 or 0
so b can't be 8. so b is 9 and a is 1.
hence (a+b) is 10.
the number is divisible by 11 if the difference between the sum of its digit at odd places and the sum of its digit at even places is either 0 or number divisible by 11.
4 a 3 | ==> here a can either be 0 or 1
9 8 4 }
13 b 7 |==> so b can be either 8 or 9
but (7+3) - (b+1) should be divisible by 11 or 0
so b can't be 8. so b is 9 and a is 1.
hence (a+b) is 10.
Soma said:
1 decade ago
I could not get why 13b7 divisible 11 was represented as (7+3) - (b+1). ?
BhargaV said:
1 decade ago
-> (7 + 3) - (b + 1)
simplify this u got (9 - b)
simplify this u got (9 - b)
Md. Mahbubur Rahaman Sheikh said:
2 decades ago
How can you got (9 - b) I cannot understand. Please, Explain
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers