Bobby's cat runs x mph. Bobby's dog runs twice as fast as his cat. If cat and dog start running away from each other how far away from each other will they be after 30 minutes?

Answer;

They will be 0.5x miles away from each other

Explanation;

Since the dog runs twice the speed of the cat

Its speed will be 2 * x = 2x mph

Now we want to know how far they will be from each other after 30 minutes

Kindly note that 30 minutes is 1/2 hour

Mathematically;

distance = speed * time

Distance of cat = x * 1/2 = 0.5x miles

Distance of dog = 2x * 0.5 = x miles

The dog is x - 0.5x miles = 0.5x miles away from the cat

i believe the correct answer is b.