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.
Gurleen said:
7 years ago
Not clear. Please explain in an easy way.
(1)
Prashasti said:
5 years ago
Thanks @Amrith.
(1)
Shiwani said:
9 years ago
Why we added x instead of 10x to (x+2)?
(1)
Abc said:
2 decades ago
how did u get 10x here
(1)
Ayushi said:
6 years ago
Hi, Can anyone tell me, how we get (22x^2 + 26x - 140)?
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.
Pratyasha said:
8 years ago
Because a 2-digit number is represented as 10x+y.
Naina said:
9 years ago
Hi,
Can anyone tell me, Why we can't take 10x at ten's place and Y at an unit place?
Can anyone tell me, Why we can't take 10x at ten's place and Y at an unit place?
Nisha said:
9 years ago
How did you factorise the equation?
Please help me to solve it.
Please help me to solve it.
Ayesha said:
10 years ago
How x=2 and y=x+2=4 came?
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