There are 120 students in a school. In a survey of all students, 47 students support delaying the start of school, 53 students do not support delaying the start of school, and 20 students are indifferent to the school start time. If a student is selected at random, find the probability that the selected student is not indifferent to the school start time. Express your answer in simplified rational form.

The probability that the selected student is not indifferent to the school start time is 0.8333.

Step-by-step explanation:

Define the events s follows:

X = students support delaying the start of school

Y = students do not support delaying the start of school

Z = students are indifferent to the school start time.

The events X, Y and Z are mutually exclusive events.

That is they cannot occur together.

Compute the probability that the selected student is not indifferent to the school start time as follows:

P (Z') = P (X or Y)

        = P (X) + P (Y)

Thus, the probability that the selected student is not indifferent to the school start time is 0.8333.

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204

the answer is z7+8/5