Final answer:
To find the cost of 260g of the secret herb, calculate the unit price of $0.01 per gram and then multiply it by 260g to get $2.60 as the cost.
Step-by-step explanation:
To calculate the cost of 260g of the secret herb when 1 kilogram (1000g) costs $10, you can set up a proportion or use a unit price method:
1 kg = 1000g, and since 1 kg costs $10, this is the price for 1000g. Therefore, the price per gram is $10 / 1000g = $0.01/g. Then multiply the cost per gram by the amount of grams you want:
$0.01/g × 260g = $2.60.
So, the cost of 260g of the secret herb is $2.60.