Fraction of black pens = 2/ (2 + 5) = 2/7 answer
Multiply the cost by 1.2 (120%) to add 20% tip, and then multiply by 0.85 (85%) to take off 15%
78.96 x 1.2 x 0.85 = 80.54
Answer:

Step-by-step explanation:
Answer:
A
Step-by-step explanation:
Hyperbolic geometry is defined as a non-Euclidean geometry.
(invalidating the fifth postulate of Euclid's five fundamental postulates)
Choice B and D can be eliminated because this has nothing to do with perpendicular lines.
Choice C should be eliminated as well since that's exactly the fifth postulate of Euclid's five fundamental postulates
We are left with A by the process of elimination