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 mixture contains alcohol and water in the ratio 4 : 3. If 5 litres of water is added to the mixture, the ratio becomes 4: 5. Find the quantity of alcohol in the given mixture

 Option A: 15 litres

 Option B: 10 litres

 Option C: 30 litres

 Option D: 22 litres

 Option E: 8 litres
[EX A]: Option B

[EX Q]: Question: A grocer purchased a quantity of bananas at 3 pounds for $0.50 and sold the entire quantity at 4 pounds for $1.00. How many pounds did the grocer purchase if the profit from selling the bananas was $6.00?

 Option A:  72

 Option B:  60

 Option C:  90

 Option D:  120

 Option E:  240
[EX A]: Option A

[EX Q]: Question: The cost of producing x tools by a company is given by
C(x) = 1000 x + 5500 (in $)
a) What is the cost of 100 tools?

 Option A: 125500 $

 Option B: 125800 $

 Option C: 105900 $

 Option D: 105500 $

 Option E: 122500 $
[EX A]:
Option D