480 since 1 hour=60 minutes. Look on the graph and you can see that the line looks like its 500 but since the answer choices dont say 500 it has to be 480 which is the closest
1. The probability that your mail is delivered before 2 pm is 0.9, so the probability that the mail is delivered at 2 pm or after 2 pm (so not before 2 pm) is 1-0.9=0.1.
Remark: 0.9=9/10=90/100=90%, and 0.1 is 10%
2. Probability of the mail being delivered before 2 pm for 2 consecutive days is

3. take a look at the picture attached, the tree diagram is another method we could use.
<span>it divides two sides of a triangle equally. The midpoint of a side divides the side into two equal segments.</span>