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
$\frac{90}{100}* \frac{90}{100}= \frac{9}{10}* \frac{9}{10}= \frac{81}{100}=0.81$

3. take a look at the picture attached, the tree diagram is another method we could use.

4 0

3 years ago

The product of 5 and a number is at least 20

Natasha_Volkova [10]

this is the best thing i could find for you, good luck with your question,

5x is greater than or equal to -25

The product of 5 and a number is at least –25

we convert the given statement into inequality

product means multiplication

Let x be the unknown number

product of 5 and a number is 5x

5x is at least -25

For word at most we use <=

for word at least we use >=

So the expression becomes 5x <= -25

6 0

3 years ago

What is speed of sound in air at 100 degree celcius?​

What is speed of sound in air at 100 degree celcius?