Answer:
P(a junior or a senior)=1
Step-by-step explanation:
The formula of the probability is given by:

Where P(A) is the probability of occurring an event A, n(A) is the number of favorable outcomes and N is the total number of outcomes.
In this case, N is the total number of the students of statistics class.
N=18+10=28
The probability of the union of two mutually exclusive events is given by:

Therefore:
P(a junior or a senior) =P(a junior)+P(a senior)
Because a student is a junior or a senior, not both.
n(a junior)=18
n(a senior)=10
P(a junior)=18/28
P(a senior) = 10/28
P(a junior or a senior) = 18/28 + 10/28
Solving the sum of the fractions:
P(a junior or a senior) = 28/28 = 1
Given: ∠JNL and ∠MNK are vertical angles and m∠MNK=90°
Prove: ∠JNL is a right angle.
Statements Reasons
1. ∠JNL and ∠MNK are vertical angles. Given
2.
Vertical angle theorem
3.
Angle congruence postulate
4.
Given
5.
<u> Substitution Property of Equality</u>
Since, the measures of angle JNL and MNK are equal and the measure of angle MNK is 90 degrees. therefore, by substitution property of equality, both the angles JNL and MNK will have an equal measure.
Therefore, 
6. ∠JNL is a right angle. Definition of right angle
It depend on what d was. anything in Q3 can work for the reflection and both x and y are negative, you can say that for sure. for the actual point D, anything in Q4. in Q4 x is positive and y is negative. if d is (3,-3) then it's reflection is (-3,-3)
I’m almost done solving this