请教两道数学题！！！

奔三了

1:when the integer K is divided by 12, the remainder is 3. which of the following, when divided by 12, will have a remainder of 6? 答案是：2K，  6K，   4K+6  都对。为什么啊？怎么理解？
2:IN A certain animal population, for each of the first 3 months of life, the probability that an animal will die during that month is 1/10. for a group of 200 new born members of the population, approximately how many would be expected to survive the first 3 months of life?      答案是：146. 但是，我却是7/10乘200=140.  
麻烦解释解释吧。真的不会啊。

yarndyed

1:when the integer K is divided by 12, the remainder is 3. which of the following, when divided by 12, will have a remainder of 6? 答案是：2K，  6K，   4K+6  都对。为什么啊？怎么理解？
2:IN A certain animal population, for each of the first 3 months of life, the probability that an animal will die during that month is 1/10. for a group of 200 new born members of the population, approximately how many would be expected to survive the first 3 months of life?      答案是：146. 但是，我却是7/10乘200=140.  
麻烦解释解释吧。真的不会啊。

-- by 会员 奔三了 (2011/8/6 21:11:11)

1.K=12a+3
2k=24a+6=12x(2a)+6
6k=72a+18=12x6a+12+6=12x(6a+1)+6
4k+6=48a+18=12x(4a+1)+6

2. 200x9/10x9/10x9/10=（约等于）146

奔三了