instruction:
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:
Question: If one-third of one-fourth of a number is 15, then three-tenth of that number is

Option A: 35

Option B: 36

Option C: 45

Option D: 54

Option E: 57
answer:
Option D

question:
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
answer:
Option B

question:
Question: If each day a tree loses half its remaining leaves, what fraction of its leaves will it have lost after 6 days ?

Option A: X-1/8

Option B: X-1/16

Option C: X-1/64

Option D: X/32

Option E: X/96
answer:
Option C