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: There is one highland where planes get fuel. A plan can cover the half of the world with full tank. A plane can transfer fuel from one plane to the other in the air. How many planes are required to make one plane cover the entire world once. Starting point of the travel is the Highland and coming back to the same Highland. All the other planes giving fuels to this Plane should also come back to the same highland and they don't have to cover the entire world.

 Option A: 2

 Option B: 3

 Option C: 4

 Option D: 5

 Option E: 6

SOLUTION: Option D

PROBLEM: Question: The toll for crossing a certain bridge is $0.75 each crossing. Drivers who frequently use the bridge may instead purchase a sticker each month for $13 and then pay only $0.10 each crossing during that month. If a particular driver will cross the bridge twice on each of x days next month and will not cross the bridge on any other day, what is the least value of x for which this driver can save money by using the sticker?

 Option A: 12

 Option B: 15

 Option C: 16

 Option D: 28

 Option E: 29

SOLUTION: Option A

PROBLEM: Question: There are 10 women and 15 men in an office. In how many ways a team of a man and a woman can be selected?

 Option A: 55

 Option B: 25

 Option C: 150

 Option D: 28

 Option E: None of these

SOLUTION:
Option C