You are given a mathematical question described with an open-ended vocabulary. Questions in this task involve real-world situations, describing a mathematical problem. You are also given 4 or 5 answer options (associated with "A", "B", "C", "D", "E"). Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D', 'E'. LaTeX mathematical format (the standard way to express mathematical expressions in the typesetting software known as LaTeX) is used to express equations. Each question is solvable with high school math knowledge. Give only one answer for each question.

[Q]: Selena has two types of records, worth a total of \$41.75. Of her 25 records, b records are worth \$1.25 each and the remaining d records are worth \$2.30 each. Selena has no other types of records . Which of the following sets of equations can be solved to determine how many of each record type Selena has?
(A)\(b + d = 4l.75 3.55(b + d) = 25\) (B)\(3.55 (b + d) = 41.75 l.25(b + d) = 2.30\) (C)\(3.55(b + d) = 41.75 1.25b + 2.30d = 25\) (D)\(b + d = 25 2.30b + 1.25d = 41.75\) (E)\(b + d = 25 1.25b + 2.30d = 41.75\)
[A]: E


[Q]: From 1980 to 1990, the value of a share of stock of XYZ Corporation doubled every year. If in 1990 a share of the stock was worth \$80, in what year was it worth \$10?
(A)1984 (B)1985 (C)1986 (D)1987 (E)1988
[A]: D


[Q]: There are a total of 256 people at a party. If after every 5 minutes, half of the people present leave, how many people will still remain after 20 minutes?
(A)128 (B)80 (C)64 (D)32 (E)16
[A]:
E


