rates of work

[akredd90]

In a certain bathtub,both the cold-water and the hot-water fixtures leak . The cold-water leak alone would fill an empty bucket in "c" hours,and the hot-water leak alone would fill the same bucket in "h" hours,where c<h.If both the fixtures began to leak at the same time into the 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

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1 and 3

[jnelson0612]

Please see this thread: in-a-certain-bathtub-both-the-cold-water-and-the-hot-water-t557.html