Aptitude - Problems on Numbers - Discussion
Discussion Forum : Problems on Numbers - General Questions (Q.No. 5)
5.
A two-digit number is such that the product of the digits is 8. When 18 is added to the number, then the digits are reversed. The number is:
Answer: Option
Explanation:
| Let the ten's and unit digit be x and | 8 | respectively. |
| x |
| Then, |  |
10x + | 8 |  |
+ 18 = 10 x | 8 | + x |
| x | x |
10x2 + 8 + 18x = 80 + x2
9x2 + 18x - 72 = 0
x2 + 2x - 8 = 0
(x + 4)(x - 2) = 0
x = 2.
Discussion:
43 comments Page 5 of 5.
Sun said:
2 decades ago
We can directly check out the answer through options.
24 + 18 = 42 which gives product 8.
24 + 18 = 42 which gives product 8.
Chandra said:
2 decades ago
There are only four two digit numbers whose product of the digits is 8. They are 18, 81, 24 and 42.
We can get easily 24 is the answer.
We can get easily 24 is the answer.
Saradhapriyanka.s said:
2 decades ago
I could not understood your answer, please explain in some other way.
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