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 3 of 5.
Sudharshan said:
1 decade ago
Find Two digit number which is 4 times of digits sum and 2 times of digits multiplication.
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 ?
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?
Sabu said:
7 years ago
11x2 + 13x - 70 = 0.
(x - 2)(11x + 35) = 0.
x = 2.
How does this do?
(x - 2)(11x + 35) = 0.
x = 2.
How does this do?
(3)
Anjali said:
9 years ago
Kindly explain it in any another method, I could not understand it.
Indu said:
1 decade ago
Please tell me why we do not take 10x+y here. Please sing 10x+y.
Nisha said:
9 years ago
How did you factorise the equation?
Please help me to solve it.
Please help me to solve it.
Ayushi said:
6 years ago
Hi, Can anyone tell me, how we get (22x^2 + 26x - 140)?
Nupur said:
1 decade ago
How did 11x2+13x-70 produces (x-2)(11x+35) factors?
Pratyasha said:
8 years ago
Because a 2-digit number is represented as 10x+y.
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