Lets x to be number of students.
1) If each students get 3 ml, then all students get 3x ml.
There was n ml.
(n-3x) ml leftover
n - 3x = 5
2) If each students get 4 ml.
then all students get 4x ml.
n+21 = 4x
3)
n - 3x = 5
- (n+21 = 4x) -------> -n -21=-4x
n - 3x = 5
<span>-n -21= - 4x
</span>-3x-21=5 - 4x
x=5+21
x=26
Answer : 26 students
Check:
x=26, n-3x = 5, n-3*26=5, n=83
n+21 = 4x
83+21=4*26
104 = 104 true
Answer:
The shape and rate parameters are
and
.
Step-by-step explanation:
Let <em>X</em> = service time for each individual.
The average service time is, <em>β</em> = 12 minutes.
The random variable follows an Exponential distribution with parameter,
.
The service time for the next 3 customers is,
<em>Z</em> = <em>X</em>₁ + <em>X</em>₂ + <em>X</em>₃
All the <em>X</em>
's are independent Exponential random variable.
The sum of independent Exponential random variables is known as a Gamma or Erlang random variable.
The random variable <em>Z</em> follows a Gamma distribution with parameters (<em>α</em>, <em>n</em>).
The parameters are:

Thus, the shape and rate parameters are
and
.
Answer:
75
Step-by-step explanation:
Just make the number of regular gasoline sold to be x, while the number of premium gasoline sold to be (550-x).
That's all.
And goodluck.
Answer:
(- 1, - 2 )
Step-by-step explanation:
Given the 2 equations
x - 3y = 5 → (1)
5x - 2y = - 1 → (2)
Rearrange (1) expressing x in terms of y by adding 3y to both sides
x = 5 + 3y → (3)
Substitute x = 5 + 3y in (2)
5(5 + 3y) - 2y = - 1 ← distribute left side
25 + 15y - 2y = - 1
25 + 13y = - 1 ( subtract 25 from both sides )
13y = - 26 ( divide both sides by 13 )
y = - 2
Substitute y = - 2 in (3) for corresponding value of x
x = 5 + (3 × - 2) = 5 - 6 = - 1
Solution is (- 1, - 2 )
Answer:
C. $29.20
Step-by-step explanation:
The difference between using an electric stove and a gas stove everyday is 13 cents - 5 cents= 8 cents.
Saving 8 cents everyday.
Therefore for a year, Bryce will save 8 cents × 365days = 2920 cents
Then 2920 cents = $(2920÷100)
=$29.20