From a number of apples, a man sells half the number of existing apples plus 1 to the first customer, sells $\frac{1}{3}$ 3rd of the remaining apples plus 1 to the second customer and $\frac{1}{5}$ th of the remaining apples plus 1 to the third customer. He then finds that he has 3 apples left. How many apples did he have originally?

A train starts from station A with some passengers. At station B, 10% of the passengers get down and 100 passengers get in. At station C, 50% get down and 25 get in. At station D, 50% get down and 50 get in making the total number of passengers 200. How many passengers did board the train at station A?

A train has length of 150 meters. It is passing a man who is moving at 2 km/hour in the same direction of the train, in 3 seconds. Find out the speed of the train?

Lisa gives her little brother Sam a 15-second (sec) head start in a 300-meter (m) race. During the race. Sam runs at an average speed of 5 m/sec and Lisa runs at an average speed of 8 m/sec, not including the head start. Since the time Lisa started running, what is the best approximates the number of seconds that had passed when Lisa caught up to Sam?

A typical image taken by Peter's camera is 15 megabytes in size. Peter can upload photos at a rate of 7 kilo bits per second for a maximum of 5 hours per day. If I megabit equals 1024 kilobites, what is the maximum number of images Peter can upload each day?