final averages in percentage marks

英语翻译
the slope averages about 1 in 30.but contains steep,probably vertical,cliffs,and gentle sediment-covered terraces,and near its lower reaches there is a long tailing-off which is almost certainly the result of material transported out to deep water after being eroded from the continental masses.
参考译文
坡度平均约为1/30,但其中包括陡峭的、乃至垂直的峭壁和沉积物覆盖的缓和的阶梯地带,在这个地带的低处是很长的一段尾沙地段,基本上可以断定这个地段是***块体上侵蚀下来的物质被水冲到深水处形成的.
transported out to 里的out含义是 还是是词组?如果去掉out能理解

I will remember the ancient law of averages and I will bend it to my good.中 bend it to my good
bend it to my good 应该怎么翻译?谢谢高人

the law of averages（平均法则）和the laws of grammar（语法规则）区别一个law是单数,另一个law是复
两句话中,为什么一个law是单数,另一个law是复数,后面的average和grammar也有单数和复数的区别呢?

In a race from point X to poinY and back,Jack averages 30 miles per hour to point Y and 10miles pe
hour back to point X.Sandy averages 20 miles per hour in both directions.Between Jack and Sandy,who finish first?请帮忙翻译,并给出答案,
A.Jack B.Sandy C They tie D.Neither
为何？没想通？