Aptitude - Problems on Numbers - Discussion
Discussion Forum : Problems on Numbers - General Questions (Q.No. 9)
9.
In a two-digit, if it is known that its unit's digit exceeds its ten's digit by 2 and that the product of the given number and the sum of its digits is equal to 144, then the number is:
Answer: Option
Explanation:
Let the ten's digit be x.
Then, unit's digit = x + 2.
Number = 10x + (x + 2) = 11x + 2.
Sum of digits = x + (x + 2) = 2x + 2.
(11x + 2)(2x + 2) = 144
22x2 + 26x - 140 = 0
11x2 + 13x - 70 = 0
(x - 2)(11x + 35) = 0
x = 2.
Hence, required number = 11x + 2 = 24.
Discussion:
42 comments Page 2 of 5.
Tejaswi said:
7 years ago
2 digit number can be represented as 10x+y.
Let's take a 2-digit number 52.
it can be written as 50+2.
50=10*5.
So "10 * 5 +2" (10x+y).
Let's take a 2-digit number 52.
it can be written as 50+2.
50=10*5.
So "10 * 5 +2" (10x+y).
(1)
Soumya said:
1 decade ago
Explanation about 10x
eg:123 means 100+20+3
in question its given tat unit's digit exceeds its ten's digit by 2 ,so units place is x+2 n tens place is 10x....
eg:123 means 100+20+3
in question its given tat unit's digit exceeds its ten's digit by 2 ,so units place is x+2 n tens place is 10x....
Avdhesh said:
1 decade ago
@Venkat.
We want the product of digit (ie. 24) and its sum (ie 2+4) = 144.
And for option C number is 42 doesn't satisfy the condition.
We want the product of digit (ie. 24) and its sum (ie 2+4) = 144.
And for option C number is 42 doesn't satisfy the condition.
Prsd said:
2 years ago
The possibilities are 24 and 46.
Product × Sum = 144,
In case of 24 => X × 6 = 144,
Hence, X=24.
Therefore 24 is the right answer.
Product × Sum = 144,
In case of 24 => X × 6 = 144,
Hence, X=24.
Therefore 24 is the right answer.
(8)
Avdhesh said:
1 decade ago
@Shikha.
Hey if we add 10x to (x+2) we will get that number. And when we add x to (x+2) we get the sum so. Hope I clarify a bit.
Hey if we add 10x to (x+2) we will get that number. And when we add x to (x+2) we get the sum so. Hope I clarify a bit.
Moti Chavan said:
8 years ago
Yes, right @Pratyasha.
The 2 digit number is represented as 10x+y. But by taking like this I'm not getting answer.
The 2 digit number is represented as 10x+y. But by taking like this I'm not getting answer.
Shikha said:
1 decade ago
I don't get this step.
Sum of digits = x + (x + 2) = 2x + 2.
Why we added x instead of 10x to (x+2).
Sum of digits = x + (x + 2) = 2x + 2.
Why we added x instead of 10x to (x+2).
GAURAV said:
6 years ago
This type of problem doesn't gives a correct answers, as question sentences are itself confusing.
(4)
Siddhesh said:
7 years ago
The product of the given number and sum of digit means;
24 * (2+4) = 144.
So, the answer is 24.
24 * (2+4) = 144.
So, the answer is 24.
(19)
Ashmis said:
1 decade ago
I just divided the 144 with the options. 144 is completely divided by 24 so that is the answer.
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