Answer:
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.
