(1) A fish killing virus has invaded lake Superior. When the outbreak was detected there were 2000 infected fish and the rate of growth was 200 fish...

(1) A fish killing virus has invaded lake Superior. When the outbreak was detected there were 2000 infected fish and the rate of growth was 200 fish per week initially. The number of infected fish is growing at a rate proportional to the the number of infected fish.

What is the differential equation which describes this ?

Need to use t for the number of weeks since the outbreak is discovered. ________________________________

(2)John drives at one constant speed for the first and last hour of a journey. He drives at a different constant speed for the rest of the journey. The total distance he drives is 400 miles and it takes him 5 hours. After two hours of driving he is 150 miles from his start. How fast did he drive in mph for the first hour ? ___________