Answer:
x=0
Step-by-step explanation:
13x-2 = 10x-2
Subtract 10x from each side
13x-10x-2 = 10x-2 -10x
3x-2 = -2
Add 2 for each side
3x-2+2 = -2+2
3x= 0
divide by 3
3x/3 = 0/3
x =0
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:
Step-by-step explanation:
Given that a fair coin is flipped twelve times.
It means the number of possible sequences of heads and tails would be:
2¹² = 4096
We can determine the number of ways that such a sequence could contain exactly 9 tails is the number of ways of choosing 9 out of 12, using the formula

Plug in n = 12 and r = 9


∵ 
∵ 

Thus, the probability will be:



Thus, the probability of the coin landing tails up exactly nine times will be:
11/15=.7333333 so the one with the line above the 3 only
Fraction is used to rename 5/6