A forest is burning in a valley. If the fire burns for h hours, the cost of the lost timber is 1000h dollars. They estimate that x firefighters can stop the fire in 3600/x hours. The cost for each firefighter is $20 (transportation)plus $25 per hour (salary/ food). A. Let C be the cost of the fire. C will depend on both h and x . Give a formula for C in terms of x and h. B. Give a formula that relates x and h. C. How may firefighters should be used if the cost C of the fire is to be minimized?