Explanation: A number is divisible by 25 if its last two digits are divisible by 25. The last two digits are q5, so \(q5\) must be 25 or 75. Thus, \(q\) must be 2 or 7. The two-digit number \(pq\) must be a multiple of 13. The multiples of 13 are 13, 26, 39, 52, 65, 78, 91. Since \(q\) is 2 or 7, \(pq\) can be 52 or 91. The number formed is \(2pq5\). If \(pq=52\), the number is 2525, which is divisible by 25. If \(pq=91\), the number is 2915, which is not divisible by 25. Thus, \(pq = 52\).
