Cierto tipo de mezcla contiene 5kg de arena y 3 kg de cemento: un constructor necesita 12 toneladas de esta mezcla. ¿qué cantidad se necesita de arena y de cemento?

the sand and cement needed is 7.5 kg and 4.5 kg respectively

Step-by-step explanation:

The computation of the sand and cement needed is shown below:

Given that

The mix of sand and cement is 5kg and 3kg i.e. its ratio is 5:3

And there is a 12kg of mix of both things

So individually it required

For sand = 12 × 5 ÷ 8

= 7.5 kg

For cement = 12 × 3 ÷ 8

= 4.5 kg

Hence, the sand and cement needed is 7.5 kg and 4.5 kg respectively

The answer is -3.

Explanation:
The slope of a line is the ratio of how many units the line moves up or down the y axis to how many units the line moves across the x axis. In other words, it’s the rise/run of a line.

In the graph in the attached picture, every time the x axis increases by one, the y axis decreases by 3. Therefore, the ratio would be -3/1.

-3/1 is equal to -3, making the slope of this line -3.

I hope this helps! Please comment if you have any questions.