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 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
[EX A]: Option E

[EX Q]: Question: Two alloys A and B are composed of two basic elements. The ratios of the compositions of the two basic elements in the two alloys are 5 : 3 and 1 : 2, respectively. A new alloy X is formed by mixing the two alloys A and B in the ratio 4 : 3. What is the ratio of the composition of the two basic elements in alloy X ?

 Option A: 1 : 1

 Option B: 2 : 3

 Option C: 5 : 2

 Option D: 4 : 3

 Option E: 7 : 9
[EX A]: Option A

[EX Q]: Question: A telephone company needs to create a set of 3-digit area codes. The company is entitled to use only digits 2, 4 and 6, which can be repeated. If the product of the digits in the area code must be even, how many different codes can be created?

 Option A: 27

 Option B: 22

 Option C: 24

 Option D: 26

 Option E: 30
[EX A]:
Option A