2/3 is exactly the same as 8/12
Plan A: 30 + 0.01m
Plan B: 20 + 0.05m
in order for 2 plans cost the same, both need to be equal
so should be
20 + 0.05m = 30 + 0.01m
answer is D. last one
20 + 0.05m = 30 + 0.01m
Use the tangent-chord theorem:
The included chord-tangent angle is half the size of the intercepted arc.
The intercepted arc is "c".
The included chord-tangent-angle is the supplement of 110=70 degrees.
Therefore from the tangent-chord theorem, 70 degrees = half the size of arc "c"
=>
arc "c" = 2*intercepted angle = 2*70 degrees = 140 degrees.
30 & 150. 150 is five times 30, and 150+30=180