Answer:

Step-by-step explanation:
The variable x, that said the number of customer that will order a nonalcoholic beverage in a sample of n customers follows a binomial distribution. Because we have n identical and independent events with a probability p of success and (1-p) of fail.
So, the probability that x customers will order a nonalcoholic beverage is:

Where n is the size of the sample and p is the probability that a customer order a nonalcoholic beverage, so replacing the values, we get:

Now, the probability that at least 7 will order a nonalcoholic beverage is equal to:

Where:

So,
is equal to:

Finally, the probability that in a sample of 10 customers, at least 7 will order a nonalcoholic beverage is equal to 0.1886
The area for that shape should be 28 because 20+8=28! Hope this helps.
OK, a triangle first of all needs to have a certain condition satisfied. The length of one side of a triangle can not equal the length of 2 sides combined. So in a triangle a + b = c, a + b can not be less than c (a + b <span>≮ c</span>). Therefore, there are only a few possibilities that will work here. Let's find them:
16, 19, 43; no
16, 19, 50; no
16, 43, 50; yes
19, 43, 50; yes
Since only 2 out of 4 form triangles, there is a 50% chance you'll pick the right segments to form a triangle.
Let x = hours to meet
train one has a 2 hour head start or 210 km head start
210 + 105x = 135x
30x = 210
x = 7 hours to meet
How much part can sally paint in an hour ?
a ÷ 7 = a/7
And what about Steve ?
a ÷ 9 = a/9
Where, a is the total area of the room.
So, let the time taken by both of them to paint the room together be 't'
So,
t(a/7 + a/9) = a
t(9a/63 + 7a/63) = a
t(16a/63) = a
t = 63/16 ≈ 4 hr