to find the range, you subtract the smaller number of the two numbers from the larger one. If there is more than two numbers, you subtract the smallest one of the group from the largest one in the group. In this situation, you do 750-50, which is 700.
It will take 20 seconds to move from one end to another because if 20 feet is moved within 5 seconds, do that 4 more times to get to 80. Finally, multiply 5 by 4 to get 20 seconds.
