下午考试,急问数学题

sdcar2010

425*17 = n

425 * 27 = 425*(10+17) = 4250 + 427*17 >2000 + n

yellllllll

有道理。。题意很难理解啊。。。

yellllllll

425*17 = n

425 * 27 = 425*(10+17) = 4250 + 427*17 >2000 + n

-- by 会员 sdcar2010 (2010/12/30 12:13:23)

大侠，140那题怎么解？

sdcar2010

425*17 = n

425 * 27 = 425*(10+17) = 4250 + 427*17 >2000 + n

-- by 会员 sdcar2010 (2010/12/30 12:13:23)

大侠，140那题怎么解？

-- by 会员 yellllllll (2010/12/30 12:20:16)

I added more explanation to my original reply. Read it again on the first page.

chouchouzzcc

NN能帮忙解释一下130这个吗？谢谢！

130. PS，已知P,Q都是整数，用q去除p余数为q/2。求q
（1）q是质数
（2）q<17

1) q=2.  Sufficient
2) insufficient

Choose A

-- by 会员 sdcar2010 (2010/12/30 12:06:18)

yellllllll

425*17 = n

425 * 27 = 425*(10+17) = 4250 + 427*17 >2000 + n

-- by 会员 sdcar2010 (2010/12/30 12:13:23)

大侠，140那题怎么解？

-- by 会员 yellllllll (2010/12/30 12:20:16)

I added more explanation to my original reply. Read it again on the first page.

-- by 会员 sdcar2010 (2010/12/30 12:21:54)

“A事件发生orB事件发生orAB同时发生的概率是0.6” 这个能知道AB是等事件吗？

sdcar2010

NN能帮忙解释一下130这个吗？谢谢！

130. PS，已知P,Q都是整数，用q去除p余数为q/2。求q
（1）q是质数
（2）q<17

1) q=2.  Sufficient
2) insufficient

Choose A

-- by 会员 sdcar2010 (2010/12/30 12:06:18)

-- by 会员 chouchouzzcc (2010/12/30 12:26:01)

已知P,Q都是整数，用q去除p余数为q/2

p = m*q + q/2.  So q is an even number

1) q is prime.  The only even number that is also prime is 2.  Sufficient.
1) q<17.  q is even. q could be 2, 4, 6, 8, ..., 16.  Insufficient.

sdcar2010

425*17 = n

425 * 27 = 425*(10+17) = 4250 + 427*17 >2000 + n

-- by 会员 sdcar2010 (2010/12/30 12:13:23)

大侠，140那题怎么解？

-- by 会员 yellllllll (2010/12/30 12:20:16)

I added more explanation to my original reply. Read it again on the first page.

-- by 会员 sdcar2010 (2010/12/30 12:21:54)

“A事件发生orB事件发生orAB同时发生的概率是0.6” 这个能知道AB是等事件吗？

-- by 会员 yellllllll (2010/12/30 12:29:42)

No. It means (A not B) + (B not A) + (A & B) = 0.6.  And we want to know (A not B).

yellllllll

NN能帮忙解释一下130这个吗？谢谢！

130. PS，已知P,Q都是整数，用q去除p余数为q/2。求q
（1）q是质数
（2）q<17

1) q=2.  Sufficient
2) insufficient

Choose A

-- by 会员 sdcar2010 (2010/12/30 12:06:18)

-- by 会员 chouchouzzcc (2010/12/30 12:26:01)

已知P,Q都是整数，用q去除p余数为q/2

p = m*q + q/2.  So q is an even number

1) q is prime.  The only even number that is also prime is 2.  Sufficient.
1) q<17.  q is even. q could be 2, 4, 6, 8, ..., 16.  Insufficient.

-- by 会员 sdcar2010 (2010/12/30 12:37:52)

大侠，也许是我多虑了...还请谅解... 你总写英文，外国人会偷窃我们的劳动果实的，现在国际竞争很激烈，cder不容易，不要帮他们吧。。。

yellllllll

425*17 = n

425 * 27 = 425*(10+17) = 4250 + 427*17 >2000 + n

-- by 会员 sdcar2010 (2010/12/30 12:13:23)

大侠，140那题怎么解？

-- by 会员 yellllllll (2010/12/30 12:20:16)

I added more explanation to my original reply. Read it again on the first page.

-- by 会员 sdcar2010 (2010/12/30 12:21:54)

“A事件发生orB事件发生orAB同时发生的概率是0.6” 这个能知道AB是等事件吗？

-- by 会员 yellllllll (2010/12/30 12:29:42)

No. It means (A not B) + (B not A) + (A & B) = 0.6.  And we want to know (A not B).

-- by 会员 sdcar2010 (2010/12/30 12:39:19)

攒了！通透！经典：）