Thread: Number system question

Q. If 653xy is divisible by 80 then find the value of x+y.

80 = 8 * 10

So y = 0 (As it is divisible by 10)

Now 3x0 should be divisible by 8. X can be both 2 and 6.

The answer is 6. As per my calculation it can be both 2 and 6. Am i right ?

Originally Posted by vivek_master146

Q. If 653xy is divisible by 80 then find the value of x+y.

80 = 8 * 10

So y = 0 (As it is divisible by 10)

Now 3x0 should be divisible by 8. X can be both 2 and 6.

The answer is 6. As per my calculation it can be both 2 and 6. Am i right ?

65320 is not divisible by 80.

Originally Posted by vivek_master146

Q. If 653xy is divisible by 80 then find the value of x+y.

80 = 8 * 10

So y = 0 (As it is divisible by 10)

That's correct.

Now 3x0 should be divisible by 8. X can be both 2 and 6.

The answer is 6. As per my calculation it can be both 2 and 6. Am i right ?

If you have divided 653x0 by 10 you are left with 653x.

Therefore 53x must be divisible by 8.