Answer:
93% probability of a student taking a calculus class or a statistics class
Step-by-step explanation:
We solve this problem building the Venn's diagram of these probabilities.
I am going to say that:
A is the probability that a student takes a calculus class.
B is the probability that a student takes a statistics class.
We have that:

In which a is the probability that a student takes calculus but not statistics and
is the probability that a student takes both these classes.
By the same logic, we have that:

The probability of taking a calculus class and a statistics class is 0.07
This means that 
The probability of taking a statistics class is 0.90
This means that
. So



The probability of a student taking a calculus class is 0.10
This means that 



What is the probability of a student taking a calculus class or a statistics class

93% probability of a student taking a calculus class or a statistics class
Answer:
1/10
Step-by-step explanation:
For 1 the equation of the parabola is y = x^2 - 8x + 3
For 2 the equation of the parabola is y = -2x^2 - 3x + 1
For 3 the equation of the parabola is y = -x^2 + 5x - 4
The amount of balls in a given layer can be found by squaring the layer it is in
4 layers
top layer (1st) is 1
2nd is 4
3rd layer is 9
4th is 16
add them up
1+4+9+16=30
30 in that pyramid