Answer:
if it's less than 7.66km use Royal, if more than 7.66 use Queen's
Step-by-step explanation:
To get the answer you can set up mutliple equations
For Queen's Cab Company
2.70 + 0.20x = ?
for Royal Cab Company
1.55 + 0.35x = ?
Since you didn't give a distance which is what will determine which is cheaper we can solve as a set of equations.
2.70 + 0.20x = 1.55 + 0.35x
1.15 = .15x
x = 7.66
So this lets you know that at 7.66 km Royal cab company becomes more expensive due to their pence per km.
So if it's less than 7.66km use Royal, if more use Queen's