You were not driving for 12 hours.
<em><u>Explanation</u></em>
Distance to the vacation spot is 1500 miles and you estimate that you drove an average speed of 50 mph.
<u>Relationship between distance, speed and time</u> is.......

So, the <u>number of hours you drove</u> 
Given that, including rest stops it’s takes you 42 hours to get to the vacation spot.
Thus, the number of hours you were not driving 
Answer:
For each part, find how many numbers have the stated characteristic, then divide by 21.
e.g. multiples of 5:
these would be 10, 15, 20, 25, and 30
so prob (a multiple of 5 ) = 5/21
Do the others the same way
I think the answer is d hope this helps
The answer is 3 of each. 3X7=21; 14X3=42, and 42+21= 63.