GMAT Question of the Day (Nov 15): Statistics and Sentence Correction

Math (PS)

Which set has the greatest standard deviation?

I. 1, 3, 5, 7, 9
II. 2, 4, 6, 8, 10
III. 1, -1, -3, -5, -7

(A) I
(B) II
(C) III
(D) I and II
(E) none

OA and Explanation

Verbal (SC)

Salsa Dancers warm up before every performance by doing a series of warm-up and stretching exercises, and it reduces the chance of injury.

(A) exercises, and it reduces
(B) exercises, which reduces
(C) exercises, reducing
(D) exercises, the routine reduces
(E) exercises, so the routine reduces

OA and Explanation