A watch was sold in both Shop A and Shop B. The usual price of the watch was the same in both shops. During a sale, Shop A offered a 20% discount for the watch and Shop B offered a 30% discount on the same watch. Jason had some money. He wanted to buy the watch from Shop A but he needed $24 more. So Jason bought the watch from Shop B and had $4 left. How much money did Jason have at first?
If the original cost was x, then we know that
0.80x - 24 = 0.70x + 4
Now just solve for x, and then you can figure the money he had.