Answer:
A. r!
Step-by-step explanation:
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

Permutations formula:
The number of possible permutations of x elements from a set of n elements is given by the following formula:

Permutation of n things taken r at a time

Combination of n things taken r at a time:

Division:

So the correct answer is:
A. r!
the complete question is
While driving in an exotic foreign land you see a speed limit sign on a highway that reads 180,000 furlongs per fortnight. How many miles per hour is this? (One furlong is 1/8 mile, and a fortnight is 14 days. A furlong originally referred to the length of a plowed furrow.)
Step 1
<u>convert (furlongs per fortnight) to (miles per fortnight)</u>
180,000 furlongs per fortnight=180,000*(1/8)=22,500 miles per fortnight
Step 2
<u>convert miles per fortnight to miles per hour</u>
1 day=24 hour
14 day=24*14=336 hours
22,500 miles per fortnight=22,500/336=66.96 mph
therefore
<u>the answer is</u>
66.96 mph
Ur multiplying by 1/4 to get to the next number...so ur next number is 1/4