a clock store sold a certain clock to a collector for 35 percent more than the store had originally paid for the clock . when the collector tried to resell the clock to the store , the store bought it back at 15 percent of what the collector had paid . the shop then sold the clock again at a profit of 65 percent on its buy - back price . if the difference between the clock ' s original cost to the shop and the clock ' s buy - back price was $ 105 , for how much did the shop sell the clock the second time ?