这是我这一回里不会的问题,有点多有5题,麻烦大家耐心帮我解一下,感激不尽!! GWD3 2 On Saturday morning, Malachi will begin a camping vacation and he will return home at the end of the first day on which it rains. If on the first three days of the vacation the probability of rain on each day is 0.2, what is the probability that Malachi will return home at the end of the day on the following Monday? A. 0.008 ﹡B. 0.128 C. 0.488 D. 0.512 E. 0.640 Q7: If x < 0, then √(-x ‧∣x∣) is ﹡A. –x B. -1 C. 1 D. x E. √x 这一题我算是D,不懂为什麽是A? Q18: Last year the price per share of Stock X increased by k percent and the earnings per share of Stock X increased by m percent, where k is greater than m. By what percent did the ratio of price per share to earnings per share increase, in terms of k and m? A. k/m % B. (k-m) % C. [100(k-m)]/(100+k) % ﹡D. [100(k-m)]/(100+m) % E[100(k-m)]/(100+k+m) % Q33: A photographer will arrange 6 people of 6 different heights for photograph by placing them in two rows of three so that each person in the first row is standing in front of someone in the second row. The heights of the people within each row must increase from left to right, and each person in the second row must be taller than the person standing in front of him or her. How many such arrangements of the 6 people are possible? ﹡A. 5 B. 6 C. 9 D. 24 E. 36 Q34: If Line k in the xy-plane has equation y = mx + b, where m and b are constants, what is the slope of k? (1) k is parallel to the line with equation y = (1-m)x + b +1. (2) k intersects the line with equation y = 2x + 3 at the point (2, 7). ANS.A 这题(2)我知道,但(1)我斜率有些部份有点忘了,麻烦帮我解释! 谢谢解答!! --

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