Task: Question Answering
Input (English): Problem: a clock store sold a certain clock to a collector for 20 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 50 percent of what the collector had paid . the shop then sold the clock again at a profit of 80 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 $ 100 , for how much did the shop sell the clock the second time ? 
Options: a ) $ 270 , b ) $ 250 , c ) $ 240 , d ) $ 220 , e ) $ 200
Output (English): a