Scoretop 31 - Question 8 - Remainder

[akay]

A bit confusing...

When positive integer is x is divided by 5, the remainder is 3; and when x is divided by 7, the remainder is 4. When positive integer y is divided by 5, the remainder is 3; and when y is divided by 7, the remainder is 4. If x > y, which of the following must be a factor of x - y?

A. 12
B. 15
C. 20
D. 28
E. 35

If it helps the answer is 35.

[niks_01.27]

If x > y and has to fit into the conditions as in the question, y should be incremented by a number which is divisible my both 5 and 7 (LCM => 35).
So if you subtract x - y; 35 must be a common factor.

So answer should be E.

[akay]

thanks niks

[kajcha]

akay, can you please make sure not to put answer with your question or just hide it... it just helps in better thinking - a friendly request...

Thanks