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 4 of 5.
Venkat said:
1 decade ago
If option A is correct according to naresh why not C, as it is same to a when we add up ?
Indu said:
1 decade ago
Please tell me why we do not take 10x+y here. Please sing 10x+y.
Ashmis said:
1 decade ago
I just divided the 144 with the options. 144 is completely divided by 24 so that is the answer.
Sandeep said:
1 decade ago
Nice explanation naresh.
Naresh said:
1 decade ago
Its not the case of confusing..its the case of time consuming...just check the options only two options may give the answer..24 and 46... now apply the second condition given in the problenm to these two options
24*(2+4)=144.. so this is the correct answer
24*(2+4)=144.. so this is the correct answer
(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....
Karthi said:
1 decade ago
It is confusing please explain about 10x.
Kranth said:
1 decade ago
Confusing in the answer. There is not clearence.
Gupta said:
1 decade ago
In the question it is clearly mentioned that units digit is 2 more than tens digit, then by observing the options only in 24 units digit(i.e.4 ) is more than 2 with tens digit(i.e.2).
Bharathi said:
1 decade ago
How unit digit is x+2 ?
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