Aptitude - Problems on Numbers - Discussion
Discussion Forum : Problems on Numbers - General Questions (Q.No. 13)
13.
A number consists of 3 digits whose sum is 10. The middle digit is equal to the sum of the other two and the number will be increased by 99 if its digits are reversed. The number is:
Answer: Option
Explanation:
Let the middle digit be x.
Then, 2x = 10 or x = 5. So, the number is either 253 or 352.
Since the number increases on reversing the digits, so the hundred's digits is smaller than the unit's digit.
Hence, required number = 253.
Discussion:
22 comments Page 1 of 3.
Ramya said:
2 decades ago
I dont understand concept .....pls post ur answers
Laxmikanta said:
1 decade ago
Lets Suppose three digits are a,b,c
Than a+b+c=10
But b=a+c (given)
a+c+b=10
(a+c)+b=10
b+b=10
b=10/2=5
so the middle digit is 5
so a=3or2 and c=3or2 (3+2=5)
thats why the number is either 253 or 352
But the actual no is 99 less than the reverse no.
352-253=99
: . so the no is 253
Than a+b+c=10
But b=a+c (given)
a+c+b=10
(a+c)+b=10
b+b=10
b=10/2=5
so the middle digit is 5
so a=3or2 and c=3or2 (3+2=5)
thats why the number is either 253 or 352
But the actual no is 99 less than the reverse no.
352-253=99
: . so the no is 253
(1)
Abhihek said:
1 decade ago
Another way--
let the digits be x,y,z.
given-
x+y+z=10
and
y=x+z
then=> y+y=2y=10=>y=5
number is either 253 or 352..
the number is increased by 99,when reversed.
therefore answer is 253.
let the digits be x,y,z.
given-
x+y+z=10
and
y=x+z
then=> y+y=2y=10=>y=5
number is either 253 or 352..
the number is increased by 99,when reversed.
therefore answer is 253.
Suresh said:
1 decade ago
3 digit sum of 253 (2+5+3 = 10) and 2+3 = 5 for middle number.
3 digit sum of 352 (3+5+2 = 10) and 3+2 = 5 for middle number.
Given,
352-253 = 99.
Hence, 352 = 253 smaller number is = 253.
3 digit sum of 352 (3+5+2 = 10) and 3+2 = 5 for middle number.
Given,
352-253 = 99.
Hence, 352 = 253 smaller number is = 253.
Malik Muhammad Mehran said:
1 decade ago
Here, conclusion of 352 and 253 is confusing for some people.
Let me explain:
Read last lines REVERSING DIGITS INCREASES BY 99 (gives the answer of the question).
So the present number small according to this statement.
And 253 is smaller than 352 so 253 is the correct answer.
Let me explain:
Read last lines REVERSING DIGITS INCREASES BY 99 (gives the answer of the question).
So the present number small according to this statement.
And 253 is smaller than 352 so 253 is the correct answer.
Shubhrank said:
1 decade ago
2x = 10.
Implies, x=5,
So number could be 253 or 352 and 154 or 451.
Now, (100a + 50 + b) - (100b + 50 + a) = 99.
And a+b = 5,
On solving, number = 253.
Implies, x=5,
So number could be 253 or 352 and 154 or 451.
Now, (100a + 50 + b) - (100b + 50 + a) = 99.
And a+b = 5,
On solving, number = 253.
Anagha said:
1 decade ago
Can you please explain why the numbers can't be 154 and 451?
Mahendra Meena said:
1 decade ago
According to Question if we add the number was reversed.
If we add in 154+99 = 253 but 154 reversed is 451.
In Question option B if we add 253+99 = 352, and 253 reversed 352.
If we add in 154+99 = 253 but 154 reversed is 451.
In Question option B if we add 253+99 = 352, and 253 reversed 352.
Bhavna said:
1 decade ago
@Anagha.
For these type of questions we have to go with the options. Because there are so many 3 digit numbers like that (132 etc....) but we don't have those options here.
For these type of questions we have to go with the options. Because there are so many 3 digit numbers like that (132 etc....) but we don't have those options here.
Kumarraju said:
1 decade ago
Please explain once for simple method.
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