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.

[EX Q]: Question: A bag contains 12 red marbles. If someone were to remove 2 marbles from the bag, one at a time, and replace the first marble after it was removed, the probability that neither marble would be red is 49/64. How many marbles are in the bag?

 Option A: 24

 Option B: 48

 Option C: 60

 Option D: 96

 Option E: 84
[EX A]: Option D

[EX Q]: Question: Calculate the sum of first 60 natural numbers.

 Option A: 1839

 Option B: 2830

 Option C: 1830

 Option D: 1831

 Option E: 1835
[EX A]: Option C

[EX Q]: Question: On a sum of money, the S.I. for 2 years is Rs. 660, while the C.I. is Rs. 696.30, the rate of interest being the same in both the cases. The rate of interest is?

 Option A: 10%

 Option B: 10.5%

 Option C: 12%

 Option D: 13%

 Option E: None of these
[EX A]:
Option D