Probability that you will get exactly 4 tails, if you flip a fair coin 7 times is: 
Step-by-step explanation:
We need to find the probability that you will get exactly 4 tails, if you flip a fair coin 7 times.
This is the combination question.
The total combinations will be: 2^7=128
Now, finding number of ways we can get exactly 4 tiles:
We will use the formula:

in our given question, n= 7, k= 4
Putting values:

So, Probability that you will get exactly 4 tails, if you flip a fair coin 7 times is: 
Keywords: Probability
Learn more about Probability at:
#learnwithBrainly
Answer: y-8
Step-by-step explanation:
Answer:
7 hours
Step-by-step explanation:
47+23=70
1hour = 70 toys
? = 490 toys
Then you cross multiply:
1hour*490 toys= 490/70 = 7 hours
____________
70 toys
Answer:
last test grade=x x ≥ 79 so 79%
Step-by-step explanation:
(84/5)+(88/5)+(95/5)+(104/5)+(x/5) ≥ 90
Simplify: (371/5)+(x/5) ≥ 90
Subtract (371/5) from both sides
Then you have (x/5) ≥ (79/5)
Then multiply both sides by 5 and you have x ≥ 79
P.S. If it was helpful please consider giving me brainliest. =)