A cold water pipe can fill a swimming pool in 4 hours, and a hot water pipe in 6 hours. If cold water pipe is turned on and hot water pipe is turned on 3 hours later then how long will it take them to fill the pool together?

answer = 5

Step-by-step explanation:

A cold water pipe can fill a swimming pool in 4 hours

And a hot water pipe in 6 hours.

If cold water pipe is turned on and hot water pipe is turned on 3 hours later

6-4 = 2

2+3 = 5

5 answer

0.6 of an hour

Step-by-step explanation:

A cold pipe takes 4h hours so we can assume ¼ of our job is done in one hour.

After 3 hours go by with the cold pipe on, we have ¼ of the job left.

Now we have our hot pipe, which takes 6 hours for the entire pool, so we can assume that it has a rate of ⅙ per hour. Now since these two pipes are working together we can add them.

⅙ + ¼ = ⁵/₁₂

Now we divide.

Since at the start 3 hours had gone by with the cold pipe that would have been ¾ of our time so, 1 - ¾ = ¼

¼ ÷ ⁵/₁₂ = ⅗ or 0.6 of an hour

c. 27 units.

step-by-step explanation:

we are told that in circle a, ∠bae ≅ ∠dae.

we can see from our given diagram that in and ;

, as these are radii of our given circle.

therefore, by sas congruence postulate.

hence, side be will be equal to side de as corresponding parts of congruent triangles are congruent. so we can set an equation to find the value of x as:

now let us substitute x=17 in the expression for the length of be.

therefore, length of be will be 27 units and option c is the correct choice.

the image is given below

since the options are not given so we draw it from the equation

the given equation is

y = (x-1) (x+4)

y = y² + 3x - 4

the above equation is a quadratic equation which will have two roots. if we draw the graph for it, it will look like this