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: 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
answer:
Option D

question:
Question: A group of boy scouts and girls scouts is going on a rafting trip. 45% of the scouts arrived with signed permission slips. If 60% of the scouts were boy scouts and 25% of the boy scouts arrived with signed permission slips, then what percentage of the scouts were girl scouts who arrived with signed permission slips?

Option A: 20

Option B: 21

Option C: 25

Option D: 28

Option E: 30
answer:
Option E

question:
Question: There are two water tanks A and B, A is much smaller than B. While water fills at the rate of one liter every hour in A, it gets filled up like 10, 20, 40, 80, 160 in tank B. (At the end of first hour, B has 10 liters, second hour it has 20, third hour it has 40 and so on). If tank B is 1/32 filled after 21 hours, what is the total duration required to fill it completely?

Option A: 22

Option B: 28

Option C: 269

Option D: 26

Option E: 82
answer:
Option D