Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 106)
106.
If x and y are the two digits of the number 653xy such that this number is divisible by 80, then x + y = ?
2 or 6
4
4 or 8
8
None of these
Answer: Option
Explanation:

80 = 2 x 5 x 8

Since 653xy is divisible by 2 and 5 both, so y = 0.

Now, 653x is divisible by 8, so 13x should be divisible by 8.

This happens when x = 6.

x + y = (6 + 0) = 6.

Discussion:
23 comments Page 3 of 3.

Saurabh said:   1 decade ago
"Now, 653x is divisible by 8, So 53x should be divisible by 8".

But by the test of divisibility value for x is 6.
But for what about 2?

Martin said:   1 decade ago
The answer is 6.

Let the number be 65300.

65300/80 = 816.25; this is not a whole number.

Try 816 x 80 = 65280 - not quite there so add 80.

65280+ 80 = 65360.
6 + 0 = 6.

Vishnu said:   1 decade ago
"Now, 653x is divisible by 8, so 13x should be divisible by 8".

In the above statement why 13x should be divisible by 8. Shouldn't it be like 53x should be divisible by 8.


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