Problem: 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 ?
Rationale: "now , in the question above , lets say the original cost of the clock to store was c $ and then it sold the same to the collector at 35 % profit . this means the clocks ' selling price was c ( 1.35 ) and this becomes cost price for the collector . now , when the collector tries to sell the same clock to the store , the store buys it for 15 % the price at which the collector bought it . thus , you get = 1.35 * 0.15 * c = 0.2025 c furthermore , the store sells the clock for the second time for 65 % profit and thus the selling price of the clock becomes = cost price of the clock for the store at buy - back * 1.65 = 1.65 * 0.2025 c finally given that c - 0.2025 c = 105 - - - - > c = 131.66 $ thus , the cost of the clock the second time around = 1.65 * 0.2025 c = 1.65 * 0.2025 * 131.66 = 43.99 $ . hence e is the correct answer ."
annotated_formula: divide(multiply(105, divide(multiply(add(105, 65), divide(add(105, 35), const_2)), 105)), subtract(divide(add(105, 35), const_2), 35))