1. How many even numbers can be formed if the digits of the number 112433 are rearranged?

2. In arranging a 10-day examination time-table involving 10 subjects and one subject per day, a teacher plans to have Mathematics, Physics and Chemistry all separate by at least one day. How many ways are possible?

Anyone please explain these to me, thank you.

PS: The answer for question 1 is 120 and the answer for question 2 is 1693440.