I think the answer is 2. Look at the photos to make sure I put the numbers in right :)
Answer:

Step-by-step explanation:
Let's define our variables. Let a represent the number of adult tickets sold, s represent the number of senior tickets sold, and r represent the number of senior tickets sold.
We know that a total of 350 tickets were sold. So, the number of adult, student, and senior tickets sold must total 350. Therefore, we can write the following equation:

We know that each adult ticket costs $4, each student ticket costs $2.50, and each senior ticket costs $2. We are given that a total of $1095 was collected. Therefore, the number of tickets multiplied by their respective price must equal $1095. So, we can write the following equation:

Finally, we know that 40 fewer senior tickets were sold than student tickets. So, however many students tickets were sold, we can subtract 40 to get the number of senior tickets sold. Therefore:

So, our system of equations is:

And we're done!
The answer is 60. You can find this out by finding the least common multiple of 10 and 12, which is 60 because 10x6=60 and 12x5=60. Hope this helps :)
Answer & step-by-step explanation:
Stationary points are the points where the first derivative is equal to zero.
Let's calculate it using the power rule (exponent comes forward, decrease exponent by 1) and the fact that the derivative is a linear operation (that is
)
The first derivative is then

Note that the last passage is not strictly needed, but it's really helpful to find stationary points, when in this next passage we set it equal to zero. Alternatively, you can use the quadratic formula if you can pull the factors out of your head right away.

These two point could be maxima, minima, or inflection points. To check them you can either see how the sign of the first derivative goes, or check the sign of the second derivative, as you're required.
The rules states that if the second derivative evaluated in that point is negative we have a maximum, if it's positive we have a minimum, and if we have a zero we keep derivating until we get a non-zero value.
In our case, the second derivative we get by calculating the derivative again and we get
. Evaluating it at both points we get

so -2 is a maximum and 3 is a minimum.