Aptitude - Problems on Numbers - Discussion

If the question is: The sum of two digits is 15 and the difference between the ten's digit and unit's digit is 3. Then the answer would be 96.

But the question given is simply: the difference between the digits is 3. He didn't said about the position of the digits.

So the given answer is correct. It cannot be determined. The answer can be 69 or 96.

Right answer should be 69. Because when asked about difference we should subtract tenth digit from unit digit. So, answer should be 69.

You are correct @Dominic.

Please, anyone tell me the correct answer to this problem.

See if the unit place is greater than the tens place the given answer is the correct.

Imagine the number 78. Here, 8 - 7 is 1, but 7 - 8 is - 1 also 7 + 8 is also 15 so the given answer is correct.

Here they are talking about the values of the digit so we take the only 7 = x and not 10x = 70.

I hope this clarifies the queries.

It can be either way around so it cannot be determined.

For example if we take 87 as the number then 8 - 7 = 1 and again 7 - 8 = 1 also 1 again 7 = 8 is 15 satisfying the (x + y) but not (x - y).

x + y = 15.
x - y = 03.
- + - (Changing signs).
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2y = 12.
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i.e y = 6 (unit place).

Substitute the value of y.

x + y = 15.
So, x + 6=15.
x = 15 - 6.
x =9 (tens place).

Then assume it as 96 and it is the correct one.

What is the correct answer?

I agree with you @Sundar. But if one of the option (69 or 96) is present in option then answer can be determined.

Cannot be determined case exists when both of the options are present and we are unable to decide among them.

Dominic answer is correct.

I don't understand the technique used guide me.