A trader hired a taxi at a rate of 15 naira per day plus 5k for each kilometre travelled. If he used it for 4 days and travelled a total distance of 400 kilometers, what was the total cost of hiring the taxi?

Answer 1

The total cost of hiring the taxi for 4 days is 15 naira/day * 4 days = <<15*4=60>>60 naira.
The total cost of travelling 400 kilometers is 5k/kilometer * 400 kilometers = 2000k.
Converting the cost to naira gives 2000k * 1000 naira/k = <<2000*1000=2000000>>2000000 naira.
Therefore, the total cost of hiring the taxi is 2000000 naira + 60 naira = <<2000000+60=2000060>>2000060 naira. Answer: \boxed{2000060}.