Опрос от журнала "8 часов": "Чем Вы питаетесь на работе?"

If a + b + c = 50, what is the value of a?
(1) c = 4a - b.
(2) The average of b and c is 2a.

A) if statement I alone is sufficient to answer the question, but statement 2
alone is not sufficient
B) if statement 2 alone is sufficient to answer the question, but statement I
alone is not sufficient
C) if both statements together are needed to answer the question, but neither
statement alone Is sufficient
D) if either statement by itself is sufficient to answer the question
E) if not enough facts are given to answer the question