SAT 1 Math Questions Help!! THANK YOU!

Question 1: Amelie leaves her house and runs south at a constant speed of 5 miles per hour. If her brother leaves the same house two hours later and skateboards south at a constant speed of 15 miles per hour, how long will it take him, in hours, to reach Amelie?

Question 2: The force of gravity between two objects, F, can be modeled by the equation F=Gm1m2/d^2, where G is a constant, m1 and m2 are the masses of the two objects, and d is the distance between them. If the distance between the two objects were to double, what would happen to the force of gravity between them?

Option A: It would double
Option B: It would decrease by half
Option C: It would quadruple
Option D: It would decrease by three quarters

Thank you for your help!!!!!