1. for all positive integers m, "m"=3m, when m is odd and "m"=1/2m when m is even. which of the following is equivalent to "9" x "6"?

81; 54; 35; 27; 18

my answer is 81，the right answer is 27. why?

2. at the end of the first quarter, the share price of a certain mutual fund was 20 percent higher than it was at the beginning of the year. at the end of the second quarter, the share price was 50 percent higher than it was at the beginning of the year. what was the percent increase in the share price from the end of the first quarter to the end of the second quarter?

20%; 25%; 30%; 33%; 40%

the right answer is 25%. why?

3.if s and t are two different numbers on the number line, is s+t equal to 0?

1) the distance between s and 0 is the same as the distance between t and 0.

2) 0 is between s and t.

the correct answer is A, my answer is C

thank you

1，81

2，25％ 设年初price为1，第一季度end1.2，第二季度end1.5

(1.5-1.2)/1.2=25%

3, A

条件是与0距离相等的两个“不同”的数