TASK DEFINITION: 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.
PROBLEM: Question: What does the hexa number E78 in radix 7.

 Option A: 12455

 Option B: 14153

 Option C: 14256

 Option D: 13541

 Option E: 14541

SOLUTION: Option D

PROBLEM: Question: If x and y are integers, what is the least positive number of 24x+18y?

 Option A: 3

 Option B: 6

 Option C: 9

 Option D: 12

 Option E: 15

SOLUTION: Option B

PROBLEM: Question: In a certain province in France there are 13 cities. If a single road segment connects only two cities, how many road segments are required in order to connect the cities so that each city is connected to all other cities with a single road segment?

 Option A: 76

 Option B: 78

 Option C: 75

 Option D: 98

 Option E: 72

SOLUTION:
Option B