Bob is doing a quality test on machine bolts. He tested 24 bolts that he randomly picked and found that 5 were defective. Based on Bob's results, what is the expected number of bolts that will be defective if he tests 840 bolts?

Which of the following are independent events? a) knowing that it is going to rain tomorrow, and bringing an umbrella to schoolb) knowing that you have to get up early tomorrow, and going to bed before 9 p.mc) knowing that it is going to rain tomorrow, and going to bed before 9 p.md) knowing that you have a test in school tomorrow, and studying thw night before