Answer:
Step-by-step explanation:
Here, the vertical space between two consecutive stairs in first 10 stairs =
⇒ The total vertical distance for 10 stairs = 
Also, The vertical space between two consecutive stairs for last 5 stairs = 
⇒ The total vertical distance for 10 stairs = 
Thus, The total vertical distance = Total vertical space for the first 10 stairs + Total vertical space for the last 5 stairs
= 
= 
= 
=
Answer:
Answer C:
Cannot be true because
is greater than zero in quadrant 2.
Step-by-step explanation:
When the csc of an angle is negative, since the cosecant function is defined as:

that means that the sin of the angle must be negative, and such cannot happen in the second quadrant. The sine function is positive in the first and second quadrant.
Therefore, the correct answer is:
Cannot be true because
is greater than zero in quadrant 2.