How many seconds will it take for a car that is traveling at a constant rate of 45 miles per hour to travel a distance of 22 yards?(1 mile = 1,160 yards)
A.8
B.9
C.10
D.11
E.12
我怎么答案算出来一个都不对啊!!
Q16:
If n is a positive integer and r is the remainder when (n-1)(n+1) is divided by 24, what is the value of r?
(1)2 is not a factor of n.
(2)3 is not a factor of n.
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.
14.the answer is wrong.it should be 45*1160=522000/3600=14.5 yards per second;22/14.5==1.52 second
16.learned from statement (1),we know that n is an odd number, therefore, (n-1)(n+1) is a consecutive even number which could be divised by 8;statement (2) indicates that n is an even number,so (n-1)(n+1) is a consecutive odd number which could be divised by 3. So, c is the correct answer.
14.the answer is wrong.it should be 45*1160=522000/3600=14.5 yards per second;22/14.5==1.52 second
16.learned from statement (1),we know that n is an odd number, therefore, (n-1)(n+1) is a consecutive even number which could be divised by 8;statement (2) indicates that n is an even number,so (n-1)(n+1) is a consecutive odd number which could be divised by 3. So, c is the correct answer.
16. (2) does not indicate n is an even number, coz n could be 5 or 7 which is divisable by 3 but still an odd number. but (1) & (2) combined together can indicate that either n-1 or n+1 is divisable by 3. Hence C is right.
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发表于 2006-7-26 09:46:00
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