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 2 of 4.
Anil sarode said:
1 decade ago
Just use the concept of divisibility of 11 and get the answer.
As number is 13b7 is divisible by 11 the difference of alternate digit must be zero or 11, so 1+b = 3+7 or (1+b) - (3+7) = 0. So you got b = 9.
A+8 = b, a+8 = 9 so a = 1, hence a+b = 10.
As number is 13b7 is divisible by 11 the difference of alternate digit must be zero or 11, so 1+b = 3+7 or (1+b) - (3+7) = 0. So you got b = 9.
A+8 = b, a+8 = 9 so a = 1, hence a+b = 10.
Kanchan said:
8 years ago
Here 4 a 3
And 9 8 4
Gives 1 3 b 7
Since 4+9=13
and at last, we are getting 13 it means the previous no has not generated any carry which can only be possible when a=1. as then we will get 8+1=9.
Therefor a=1, b=9.
a+b=10.
And 9 8 4
Gives 1 3 b 7
Since 4+9=13
and at last, we are getting 13 it means the previous no has not generated any carry which can only be possible when a=1. as then we will get 8+1=9.
Therefor a=1, b=9.
a+b=10.
(12)
Leoarul said:
1 decade ago
13b7 to know the divisibility of 11, we have to subtract sum of odd placed numbers with sum of even placed numbers.
in 13b7 odd places are 7and3
even places are b and 1.
now got it.
in 13b7 odd places are 7and3
even places are b and 1.
now got it.
Nandini B N said:
5 years ago
To know the number is divisible by 11, the rule is,
Sum of all even places=sum of all odd places.
In 13b7,
3 + 7 = 1 + b.
b=9.
Then a+8 = 9.
a = 1.
a+b = 1 + 9 = 10.
Sum of all even places=sum of all odd places.
In 13b7,
3 + 7 = 1 + b.
b=9.
Then a+8 = 9.
a = 1.
a+b = 1 + 9 = 10.
(52)
Ancy said:
9 years ago
If the number 5728abc (0<=a, b, c<=9) is exactly divisible by 12, then find the maximum value of a-b+c?
Ans: 4.
I didn't understand. Will anyone explain me?
Ans: 4.
I didn't understand. Will anyone explain me?
(1)
Mir Rokon Uddin said:
9 years ago
b - a = 8. Both a and b must be a single digit(they must come from1 to 9).
From 1 to 9 if we place a= 9 and b= 1 then the outcome will be 8. So a+b= 10.
From 1 to 9 if we place a= 9 and b= 1 then the outcome will be 8. So a+b= 10.
Biplab Kumar Halder said:
1 decade ago
If b = 9 then,
4 a 3
9 8 4
-------
13 b 7
(4+9 = 13)(a+8 = 9)(3+4 = 7).
Let see, a+8 = 9.
> a = 9-8.
> a = 1.
4 a 3
9 8 4
-------
13 b 7
(4+9 = 13)(a+8 = 9)(3+4 = 7).
Let see, a+8 = 9.
> a = 9-8.
> a = 1.
Prudvj said:
8 years ago
4 digit number 13b7 i. e divided 11.
So even-odd then :(3+7)-(1+b )apply b=9.
10-10=0.
a+b=1+9=10.
So even-odd then :(3+7)-(1+b )apply b=9.
10-10=0.
a+b=1+9=10.
(3)
Soni said:
8 years ago
Guys, 11 divisibility rule is applicable here so solve it by that rule. It will be more easy.
(3)
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 ?
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