First, calculate the comprehensive beta value of these five stocks:1.03 * 20%+1.05 *10%+0.9 *15%+1.15 * 25.

Three months later, the price of Hang Seng Index, which originally sold at 1033500, became103.35 * 8300/9000 = 9531000.

Total profit and loss =103.35-9531-7 =10400.