Clare would need 80 of fish, (1/3 of 240 is 80.) Ian would need 200g of butter (If you find the amount of each ingredient needed for a one person-pie, and multiply them by the amount of people you need to feed, you will get your answer.) We know that 80g of butter is used for 6 people, so by dividing 80 by 6, we know that for a one person-pie, you would need 13.33g of butter. Multiply 13.33 by 15 to find out how many grams of butter he would need for a pie for 15 people.
