Gabriel is making a mixer of compost and soil to use for a special plant he wants his final mix to be 2 parts compost to 8 parts potting soil he wants to end up with 12 kilograms of mix. How many kilograms of compost should Gabriel use?

Gabriel should use 2.4 kilograms of the compost.

Step-by-step explanation:

Here, the ratio of Compost : Potting Soil = 2 : 8

Also, total weight of the mix = 12 kg

Let us assume the common factor in the ratio = m

So, the amount of compost used in the mix = 2 x m = 2m

Also, the amount of Potting soil used in the mix = 8 x m = 8m

Weight of Compost + Weight of potting soil = 12 kg

⇒ 2m + 8 m = 12

or, 10 m = 12

⇒ m = 12 / 10 = 1.2, or m = 1.2

So, now the weight of the compost used = 2 m = 2 x 1.2 = 2. 4 kg

And the weight of potting soil used = 8 m = 8 x 1.2 = 9. 6 kg

Hence, Gabriel should use 2.4 kilograms of the compost.