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: In a test, sixty percent students passed in Maths and 65% in History, 40% passed in both of these subjects. If 90 students failed in maths and history both, then what is the total number of students?

 Option A: 600

 Option B: 650

 Option C: 700

 Option D: 750

 Option E: None of these
[EX A]: Option A

[EX Q]: Question: If seven machines working at the same rate can do 3/4 of a job in 30 minutes, how many minutes would it take two machines working at the same rate to do 3/5 of the job?

 Option A: 45

 Option B: 60

 Option C: 75

 Option D: 84

 Option E: 100
[EX A]: Option D

[EX Q]: Question: Cereal A is 9% sugar by weight, whereas healthier but less delicious Cereal B is 2% sugar by weight. To make a delicious and healthy mixture that is 4% sugar, what should be the ratio of Cereal A to Cereal B, by weight?

 Option A:  2:9

 Option B:  2:5

 Option C:  1:6

 Option D:  1:4

 Option E:  1:3
[EX A]:
Option B