[求助]GWD 17-21

金大小姐

GWD 17-21

Q21:

Harvey teaches a certain number of biology students in 2 classes, K and L. He can divide the students in class K into 7 groups of n students each. He can divide the students in class L into 6 groups of p students each with 1 student left over. How many students are in class L ?

(1) n = p

(2) There are 5 more students in class K than in class L.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

 Answer : C

Why the answer couldn't be A?

7n=6p+1 n=p

so, n=1

what's wrong with my answer? Help me ~Thanks

看海的猫

what's wrong in your answer is, you can't draw to the equation that 7n=6p+1 according to statement (1),there's no information that the numbers of the student in the two classes are equal.