You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

Question: In the arithmetic sequence t1, t2, t3, ..., tn, t1=23 and tn= tn-1 - 3 for each n > 1. What is the value of n when tn = 8?

 Option A: -1

 Option B: 6

 Option C: 10

 Option D: 14

 Option E: 20
Option B

Question: A bag is filled with pennies and nickels in the ratio of 5 to 3. There are 30 nickles in the bag, how many coins are there in that bag?

 Option A: 70

 Option B: 65

 Option C: 75

 Option D: 85

 Option E: 80
Option E

Question: Three numbers are in the ratio 5 : 6 : 7. The sum of its longest and smallest numbers equals the sum of the third number and 54. Find the third number?

 Option A: A

 Option B: B

 Option C: C

 Option D: D

 Option E: E

Option E