Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

[Q]: Problem: cereal a is 10 % sugar by weight, whereas healthier but less delicious cereal b is 2 % sugar by weight. to make a delicious and healthy mixture that is 3 % sugar, what should be the ratio of cereal a to cereal b, by weight ?
Options: a. 2: 9, b. 2: 7, c. 1: 7, d. 1: 4, e. 1: 3
[A]: c


[Q]: Problem: a 11 % stock yields 8 %. the market value of the stock is :
Options: a. rs. 72, b. rs. 137.50, c. rs. 112.50, d. rs. 116.50, e. none of these
[A]: b


[Q]: Problem: a welder received an order to make a 1 million liter cube - shaped tank. if he has only 2 x 3 meter sheets of metal that can be cut, how many metal sheets will be required for this order ? ( 1 cubic meter = 1000 liters )
Options: a. 92, b. 90, c. 82, d. 78, e. 100
[A]:
e