Crack GMAT Math Problem Solving and Data Sufficiency. Some good tips on solving interesting questions in Number Theory, Permutation Combination, Probability etc.
Wednesday, November 10, 2010
Descriptive Statistics - Mean and Median; Divisibility
How many numbers of 7 consecutive positive integers are divisible by 6? 1) Their average is divisible by 6 2) Their median is divisible by 12
(1) Their average is divisible by 6 This means that the 4th number is divisible by 6; therefore, the first 3 terms and the last three terms are not divisible by 6. Only one term (4th term) is divisible).
(2) Their median is divisible by 12 This means that the 4th number is divisible by 12 (and 6); therefore, the first 3 terms and the last three terms are not divisible by 6. Only one term (4th term) is divisible).
1 comments:
(1) Their average is divisible by 6
This means that the 4th number is divisible by 6; therefore, the first 3 terms and the last three terms are not divisible by 6. Only one term (4th term) is divisible).
(2) Their median is divisible by 12
This means that the 4th number is divisible by 12 (and 6); therefore, the first 3 terms and the last three terms are not divisible by 6. Only one term (4th term) is divisible).
SUFFICIENT D.
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