The least common denominator is one, since all of these numbers are actually whole numbers. They're actually all

If you mean the greatest common factor, then it's obviously
Answer:
Step-by-step explanation:
Let W = number of white cars, and Y = number of yellow cars.
There were 9 times as many white cars as yellow cars. This means that the number of white cars was 9 times more than the number of yellow cars. This can be translated by the expression:
9Y = W
The person counted 40 cars in total:
W + Y = 40
So we get the system:

In the first equation, we multiply by 9:
9W + 9Y = 360
In the second equation:
9Y= W
W-9Y = 0
Then we add the first with the second equation:
9W + 9Y + W - 9Y = 360
10 W = 360
W = 36
So He counted 36 white cars.
Hope this Helps! :)
Answer:
If Henry walks along the sidewalks, he will walk 1.7 miles in total. It will take him 17 minutes to reach the store and another 17 minutes to come back.
If Henry cuts through the city, he will walk √(1.2² + 0.5²) = 1.3 miles in total. It will take him 22.3 minutes to reach the store and another 22.3 minutes to come back.
Even though Henry will need to walk a longer distance if he walks along the sidewalks, he will be able to reach the store and back back in a shorter time than if he cuts through the city.