The cost of serving a car is partly varies with the time it takes to do work it costs 2500 for 2hrs service and 4000 for 3whole number 1/2hrs service find :@ the formulae connecting cost c and time t

Question

The cost of serving  a car is partly varies with the time it takes to do work it costs 2500 for 2hrs service and 4000 for 3whole number 1/2hrs  service find :@ the formulae connecting cost c and time t
B t when c =7500