Question

It takes 5 minutes to fill the sink using only the cold water. If both the hot water and the cold water are turned on, it takes 2 minutes to fill the sink. Which is the correct table that can be used to determine x, the time in minutes it takes to fill the sink using only the hot water?

Answer 1

The third table is correct.

Cold water alone fills 1 sink at a rate of (1 sink)/(5 minutes).

Both hot and cold water fills 1 sink at a rate of (1 sink)/(2 minutes).

Hot water alone fills 1 sink at a rate of (1 sink)/(x minutes).

Answer 2

Option C is the correct answer.

Explanation:

Let x be the time in minutes it takes to fill the sink using only the hot water.

We have it takes 5 minutes to fill the sink using only the cold water.

Rate at which cold water is flowing is given by

`r_(cold)=(1)/(5)sink/min`

It takes X minutes to fill the sink using only the cold water.

`r_(hot)=(1)/(X)sink/min`

If both of them are use it takes 2 minutes.

`\texttt{Part of sink filled by cold water = }2* (1)/(5)=(2)/(5)\\\\\texttt{Part of sink filled by hot water = }2* (1)/(X)=(2)/(X)`

Comparing the options given,

We can see option C is the correct answer.