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: a certain sum is invested at simple interest at 18 % p. a. for two years instead of investing at 12 % p. a. for the same time period. therefore the interest received is more by rs. 300. find the sum ?
Options: a. 7000, b. 2500, c. 2778, d. 2800, e. 2791

A: b
****
Q: Problem: if the price of a certain computer increased 30 percent from b dollars to 351 dollars, then 2 b =
Options: a. 540, b. 570, c. 619, d. 649, e. 700

A: a
****
Q: Problem: the average height of 35 boys in a class was calculated as 185 cm. it has later found that the height of one of the boys in the class was wrongly written as 166 cm whereas his actual height was 106 cm. find the actual average height of the boys in the class ( round off your answer to two decimal places ?
Options: a. 187.89 cm, b. 183.29 cm, c. 123.98 cm, d. 149.98 cm, e. 146.89 cm

A:
b
****