Final answer:
Mary should buy 6 bags of 1 pound trail mix to provide each of the 15 club members with a 2/5 pound bag, resulting in no leftovers.
Step-by-step explanation:
The task is to determine how many 1 pound bags of trail mix Mary should buy if each of the 15 members of her hiking club is to receive a 2/5 pound bag of trail mix without any leftovers.
First, calculate the total amount of trail mix needed by multiplying the number of members by the amount each member will receive: 15 members × 2/5 pound per member = 6 pounds.
Since trail mix is sold in 1 pound bags, Mary should buy 6 of these bags to provide the right amount of trail mix for her hiking club members without any leftovers.