Final answer:
Ian will use 27/35 of his pistachios to make trail mix, as he is using 27 pounds out of the 35 pounds he has.
Step-by-step explanation:
To find the fraction of a pound of pistachios that Ian will use for the trail mix, divide the pounds of pistachios needed for the trail mix (27 pounds) by the total pounds of pistachios Ian has (35 pounds).
So the fraction of a pound of pistachios Ian will use for the trail mix is 27/35 (choice B). With 35 pounds of pistachios on hand, and needing 27 pounds for the trail mix, the fraction of pistachios used specifically for the trail mix can be calculated by dividing the weight needed by the total weight available, which is 27/35.