Final answer:
To find the cost for 100 pumpkins when nine cost $10.80, calculate the price per pumpkin ($1.20) and then multiply by 100, resulting in a total of $120 for 100 pumpkins.
Step-by-step explanation:
To calculate how much it would cost for 100 pumpkins if nine pumpkins cost $10.80, we need to first find out the cost of one pumpkin. We do this by dividing the total cost by the number of pumpkins.
Cost of one pumpkin = $10.80 ÷ 9 pumpkins = $1.20 per pumpkin.
Now, to find the cost for 100 pumpkins, we multiply the cost of one pumpkin by 100.
Cost for 100 pumpkins = $1.20 per pumpkin × 100 pumpkins = $120.