<span>(a) This is a binomial
experiment since there are only two possible results for each data point: a flight is either on time (p = 80% = 0.8) or late (q = 1 - p = 1 - 0.8 = 0.2).
(b) Using the formula:</span><span>
P(r out of n) = (nCr)(p^r)(q^(n-r)), where n = 10 flights, r = the number of flights that arrive on time:
P(7/10) = (10C7)(0.8)^7 (0.2)^(10 - 7) = 0.2013
Therefore, there is a 0.2013 chance that exactly 7 of 10 flights will arrive on time.
(c) Fewer
than 7 flights are on time means that we must add up the probabilities for P(0/10) up to P(6/10).
Following the same formula (this can be done using a summation on a calculator, or using Excel, to make things faster):
P(0/10) + P(1/10) + ... + P(6/10) = 0.1209
This means that there is a 0.1209 chance that less than 7 flights will be on time.
(d) The probability that at least 7 flights are on time is the exact opposite of part (c), where less than 7 flights are on time. So instead of calculating each formula from scratch, we can simply subtract the answer in part (c) from 1.
1 - 0.1209 = 0.8791.
So there is a 0.8791 chance that at least 7 flights arrive on time.
(e) For this, we must add up P(5/10) + P(6/10) + P(7/10), which gives us
0.0264 + 0.0881 + 0.2013 = 0.3158, so the probability that between 5 to 7 flights arrive on time is 0.3158.
</span>
It wouldn't let me post, so I screenshotted:
X = number of days it would take Kate to paint the house by herself. .
<span>x+5 = number of days it would take Jean to paint the house by herself.</span>
<span>Together, they paint the house in 6 days: </span>
<span>1/x + 1/(x+5) = 1/6 </span>
<span>Multiply both sides by 6x(x+5) </span>
<span>6(x+5) + 6x = x(x+5) </span>
<span>12x + 30 = x^2 + 5x </span>
<span>x^2 − 7x − 30 = 0
</span>therefore the answer is A.
Answer:
B. 
Hope this helped. A brainliest would be very much appreciated. (I need 4 brainliest so I can level up) :)
Answer:
2094.4 cm³
Step-by-step explanation:
The volume of a cone =πr²h/3
Where
r = radius = Diameter/2
Diameter = 20cm, radius = 20cm/2 = 10cm
Height = 20cm
Volume of a cone = π × 10² × 20/3
Volume of a cone = 2094.3951 cm³
Approximately to the nearest tenth = 2094.4 cm³
Therefore , the volume of a cone = 2094.4 cm³
