x, y, a, and b are positive integers. When x is divided by y, the remainder is 6. When a is divided by b, the remainder is 15. Which of the following is NOT a possible value for y + b?  Pick one:
A) 24	B) 21	C) 20	D) 17	E) 15
Important note: remainder is ALWAYS less than divisor, thus y&gt;6 and b&gt;15 --&gt; y+b&gt;21.   Answer: 21.
<result>B</result>
x, y, a, and b are positive integers. When x is divided by y, the remainder is 6. When a is divided by b, the remainder is 15. Which of the following is NOT a possible value for y + b?