Respuesta :

The correct answer for the question shown above is: Gabriel should use 2 kilograms of compost.

 The explanation is shown below:

 1. To solve the exercise you must apply the following proccedure:

 2. You have that He wants it to be 2 parts compost to 10 parts potting soil and  he wants to end up with 10 grams of mix. Therefore:

 =(2/12)x12 kilograms
 =0.166x12 kilograms
 =2 kilograms