求助：几道数学题

1 On the number line ,the distance between point A and point C is 5 and the distance between point Band point C is 20.Does point C lie between point A and point B?

(1) The distance between point A and point B is 25.

(2)Point A lies to the left of point B.

2. In a certain bathtub,both the cold water and the hot water fixtures leak .The cold water leak alone would fill the same buckets in C hours ,and the hot water leak alone would fill  the same bucket in H hours ,where C<H.If both fixtures begain to leak at the same time into empty bucket  at their respective constant rates and consequently it took T hours to fill the bucket ,which of the following must be true?

(1) 0<T<H (2)C<T<H (3)C/2<T<H/2

3.Is 2x-3y<x^2?

(1)2x-3y=-2 (2)x>2 and y>0

question1---A

question2---(1)(2)(3)since T=ch/(c+h),given c<h, u can get (3)

question3---D