Answer:
- 40 popcorns and 90 pretzels sold.
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Let the number of popcorns is x and pretzels is y.
Set up equations:
- x + y = 130
- 2.5x + 2y = 280
Solve by elimination, multiply the first equation by 2 and subtract from the second equation:
- 2.5x + 2y - 2x - 2y = 280 - 2*130
- 0.5x = 280 - 260
- 0.5x = 20
- x = 20/0.5
- x = 40
Find y:
- 40 + y = 130
- y = 130 - 40
- y = 90
Answer:
0.6472 = 64.72% probability that a randomly selected page does not need to be retyped.
Step-by-step explanation:
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:
In which
x is the number of sucesses
e = 2.71828 is the Euler number
is the mean in the given interval.
Poisson distribution with an average of three errors per page
This means that 
What is the probability that a randomly selected page does not need to be retyped?
Probability of at most 3 errors, so:

In which
Then

0.6472 = 64.72% probability that a randomly selected page does not need to be retyped.
Answer:
f(x)=-13
Step-by-step explanation:
Substitute x with -2
4 times -2 is -8
-8-5 is -13
Thus f(x)=-13
Hope this helps!
Answer:
The fish is 2.25 ft above the surface at 0.375 seconds
Step-by-step explanation:
Given:
y=-16x^2+12x
x=0.375 seconds
Substitute x=0.375 into the equation
y=-16x^2+12x
= -16(0.375)^2 +12(0.375
= -16(0.140625) + 4.5
= -2.25 + 4.5
= 2.25
y=2.25 ft
The fish is 2.25 ft above the surface at 0.375 seconds