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 1 of 5.
Abc said:
2 decades ago
how did u get 10x here
(1)
Mamta said:
1 decade ago
confusing... can it be little more simplified
Bharathi said:
1 decade ago
How unit digit is x+2 ?
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).
Kranth said:
1 decade ago
Confusing in the answer. There is not clearence.
Karthi said:
1 decade ago
It is confusing please explain about 10x.
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....
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)
Sandeep said:
1 decade ago
Nice explanation naresh.
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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