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.

[Q]: Question: Working alone at its constant rate, machine K took 3 hours to produce 1/5 of the units produced last Friday. Then machine M started working and the two machines, working simultaneously at their respective constant rates, took 6 hours to produce the rest of the units produced last Friday. How many hours would it have taken machine M, working alone at its constant rate, to produce all of the units produced last Friday?

 Option A: 10

 Option B: 12

 Option C: 15

 Option D: 25

 Option E: 30
[A]: Option C


[Q]: Question: A, B and C invested Rs.6300, Rs.4200 and Rs.10500 respectively, in a partnership business. Find the share of A in profit of Rs.12700 after a year?

 Option A: 3630

 Option B: 9232

 Option C: 8828

 Option D: 2387

 Option E: 3810
[A]: Option E


[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
[A]:
Option E