Your going to have to use the distance formula for these questions which is the square root of (x sub 2 - x sub 1) + (y sub 2 - y sub 1). For number 1 your coordinates are (-5,5) and (1,-2). Substituting these values into the formula your answer for number 1 is 9.2.
If there are n coins, then the smallest (minimum) amount of coins we need to flip is 1. The reason why is because the best case scenario would be flipping all heads except the last coin which is tails. This scenario is rare if n is large, but still possible.
Divide 350 by 70 and you would get 5. This means it would take you 5 hours if you travel at a constant speed of 70 mph and you traveled 350 miles.
Answer:
I'm pretty sure it's 24.516