Tricky maths question help needed. ?

First to the conversions. 1 kilometer is 1.6 miles. N 1 hour is 3600 seconds. So 8 kilometers is 8/1.6 which is 5. 30/3600 is 0.008 hours. Now by using the formula speed = distance / time we do 5/0.0083 which gives us 625 miles per hour speed. Hope this helps