Which taxi company?

This task is about working out the cheapest option. 

two taxis

Two taxis from different firms are on a taxi stand. Heta asks the drivers their prices, and finds that Panther Taxis charge $3.00 at the start of the trip, and then $1.10 per kilometre. 
Gazelle Taxis charge $2.00 at the start, but then charge $1.20 per kilometre.

Question 1Change answer

a)  What would Panther Taxis charge for a 10 km journey? $ 

Question 1Change answer

b)  What would Gazelle Taxis charge for the same journey? $ 

Question 2Change answer

c)  Heta realises that he has to travel 15 km. Which would be the cheaper taxi?
     Explain your working or reasoning.

Question 3Change answer

d)  Complete the sentence below describing how to get the cheapest trips from the two companies:
"For journeys of up to  km, it would be cheaper to choose PantherGazelle Taxis, but for longer journeys it would be cheaper to choose PantherGazelle Taxis."