I am looking for the same answer if anyone knows it
Answer:y=9
Step-by-step explanation:
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.
Answer:
tons of high steel and
tons of low steel
Step-by-step explanation:
Let x be the number of tons of high grade steel and y be the number of tons ow low grade steel needed.
In x tons of high grade steel there are
tons of iron
tons of magnese
In y tons of low grade steel there are
tons of iron
tons of magnese
NASA orders 500 tons of steel, so

and specifies that it must be in the proportion 80% iron and 20% magnese, so

From the first equation,

Substitute it into the second equation:

Answer:
b
Step-by-step explanation: