Diana usually drives at an average rate of 30 mph. If Diana drives at an average rate of x mph, how long will it take her to get to Tony's house, which is 12 miles away?
The time it takes for Diana to get to Tony's house can be calculated using the formula:
Time = Distance / Rate
Substituting the values into the formula:
Time = 12 miles / x mph
Therefore, it will take Diana 12/x hours to get to Tony's house.