Ming Li spent $15 at the movies she earned $30 babysitting she spent $12 at the bookstore she now has $18 left how much money di
1 answer:
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Answer:
see explanation
Step-by-step explanation:
Given the 3 equations
3x + 5y + 5z = 1 → (1)
x - 2y = 5 → (2)
2x + 4y = 11 → (3)
Use (2) and (3) to solve for x and y
Multiply (2) by 2
2x - 4y = 10 → (4)
Add (3) and (4) term by term
4x = 21 ( divide both sides by 4 )
x =
Substitute this value of x into (3)
2 × + 4y = 11
+ 4y = 11 ( subtract
from both sides )
4y = ( divide both sides by 4 )
y =
Substitute the values of x and y into (1) and solve for z
3 × + 5 ×
+ 5z = 1
+
+ 5z = 1
+ 5z = 1 ( subtract
from both sides )
5z = - ( divide both sides by 5 )
z = -
Solution is
x = , y =
, z = -
Answer: a) 30, b) 0.2138, c) 0.0820
Step-by-step explanation:
Since we have given that
X be the number of calls in 1 hour = 60 minutes
Rate of one call every two minutes.
(a) What is the expected number of 911 calls in one hour?
(b) What is the probability of three 911 calls in five minutes? If required, round your answer to four decimal places.
Number of calls = 3
So, P(X=3) is given by
(c) What is the probability of no 911 calls during a five-minute period? If required, round your answer to four decimal places.
Hence, a) 30, b) 0.2138, c) 0.0820