Daily Dollar Question

The 20 Dollar Question. 
The hot water tap when it is full-on can fill a bath in 7 minutes.
What fraction of the bath can it fill in 1 minute? 1/7 √

The 40 Dollar Question.
When the cold water tap is full-on it can the
fill the bath completely in 5 minutes.
Colin has just had a long hard run and
wants to have a cold-water bath.
How long will the cold water tap take to fill
3/5 of the bath for Colin?  5 minutes √

The 60 Dollar Question.
The cold water tap when it
is full-on can fill a bath in 5
minutes.
The hot water tap when it is
full-on can fill a bath in 7
minutes.
How long will it take both taps
to fill the bath when they are
both set to full-on.
Give you answer in minutes
and seconds  2.55 √