Please help will fail class soon if not

Events a and b are independent. the probability of a occurring is 2/5. the probability of b occurring is 1/4. what is p(a and b)?

Aresearch study is done to find the average age of all u.s. factory workers. the researchers asked every factory worker in ohio what their birth year is. this research is an example of a census survey convenience sample simple random sample

Zack and tia played chess for 50 min they put the chessboard away at 11: 20 when did they start