Answer:
13
Step-by-step explanation:
where n is the number of terms, a1 is the first term and an is the last term. The sum of the first n terms of an arithmetic sequence is called an arithmetic series . Example 1: Find the sum of the first 20 terms of the arithmetic series if a1=5 and a20=62 .An arithmetic sequence is a sequence where the difference between any two consecutive terms is a constant. ... As with any recursive formula, the initial term of the sequence must be given. An explicit formula for an arithmetic sequence with common difference d is given by an=a1+d(n−1) a n = a 1 + d ( n − 1 ) .
Recall your d = rt, distance = rate * time
one car is going at 55kph, at say hmmm "t" time
the second car zooms by at 75kph, an hour later, thus " t + 1 "
notice, overtaking the 1st car, simply means, the second car comes from behind approaches the first car from behind and "gets there", at that very second, both cars have travelled a distance, say "d"
if the first car travelled "d" kilometers
for the second car to "get there" has to had travelled "d" distance as well

solve for "t"
Answer:
The towel bar should be placed at a distance of
from each edge of the door.
Step-by-step explanation:
Given:
Length of the towel bar = 
Now given length is in mixed fraction we will convert in fraction.
To Convert mixed fraction into fraction Multiply the whole number part by the fraction's denominator, then Add that to the numerator, then write the result on top of the denominator.
can be Rewritten as 
Length of the towel bar = 
Length of the door = 
can be Rewritten as 
Length of the door = 
We need to find the distance bar should be place at from each edge of the door.
Solution:
Let the distance of bar from each edge of the door be 'x'.
So as we placed the towel bar in the center of the door it divides into two i.e. '2x'
Now we can say that;

Now we will take LCM to make the denominators common we get;

Now denominators are common so we will solve the numerators.

Or 
Hence The towel bar should be placed at a distance of
from each edge of the door.