P and Q are both positive integers. When P is divided by Q, the remainder is some positive integer D, and when P is divided by (Q + 7), the remainder is also D. If P/Q = 1020.75 and P/(Q + 7) = 816.6, then which of the following gives the correct set of {D, Q}?  Select the correct option
A) {6, 12} B) {6, 15} C) {21,28} D) {9, 15} E) {15, 24}
p/q= d=p/q+7   d= .75 q   d= .6(q+7)   we get d = 21 and q = 28. Answer = {21,28}.
<result>C</result>
P and Q are both positive integers. When P is divided by Q, the remainder is some positive integer D, and when P is divided by (Q + 7), the remainder is also D. If P/Q = 1020.75 and P/(Q + 7) = 816.6, then which of the following gives the correct set of {D, Q}?