the awnser is c 10 miles per hour
This is an arithmetic sequence because each term is 7 greater than the previous term, so 7 is what is called the common difference...
Any arithmetic sequence can be expressed as:
a(n)=a+d(n-1), a=first term, d=common difference, n=term number.
We know a=1 and d=7 so:
a(n)=1+7(n-1)
a(n)=1+7n-7
a(n)=7n-6
The above is the "rule" for the nth term.
Common factors of 50: 1, 2, 5, 10, 25, 50
Common factors of 30: 1, 2, 3, 5, 6, 10, 15, 30
Common factors of 100: 1, 2, 4, 5, 10, 20, 25, 50, 100
You're welcome.