Answer:
The number of minutes advertisement should use is found.
x ≅ 12 mins
Step-by-step explanation:
(MISSING PART OF THE QUESTION: AVERAGE WAITING TIME = 2.5 MINUTES)
<h3 /><h3>Step 1</h3>
For such problems, we can use probability density function, in which probability is found out by taking integral of a function across an interval.
Probability Density Function is given by:

Consider the second function:

Where Average waiting time = μ = 2.5
The function f(t) becomes

<h3>Step 2</h3>
The manager wants to give free hamburgers to only 1% of her costumers, which means that probability of a costumer getting a free hamburger is 0.01
The probability that a costumer has to wait for more than x minutes is:

which is equal to 0.01
<h3>
Step 3</h3>
Solve the equation for x

Take natural log on both sides

<h3>Results</h3>
The costumer has to wait x = 11.53 mins ≅ 12 mins to get a free hamburger
Neutral atoms must have equal numbers of protons and electrons
Solution: 18 electrons
To find the are of a square, we simply square the value of a side
so..

Area = 25 square units
Is this a trick question? They're both a pound.
So,
Here we have the following algebraic expression:

The first term of this expression is -5x.
This term is clearly a variable term. The variable is x and its coefficient is -5.