Step-by-step reasoning process: We are trying to figure out how long it will take Peter to rake 8 bags of leaves, so we'll call that Y. And we know Peter can rake 3 bags of leaves / 15 minutes = 8 bags of leaves / Y. Next, we will multiply to find the cross - products. 3 x Y = 15 x 8 or 3Y = 120. We want to get figure out Y, so we need to get it by itself by dividing by 3, like this: 3Y / 3 = 120 / 3 or Y = 40 minutes.
The question and answer:
Question and answer: Peter is raking leaves. It takes him 15 minutes to rake 3 bags of leaves. If he keeps raking at the same rate, how long will it take him to rake 8 bags?
The answer is 40

Step-by-step reasoning process: First, we need to determine the overall number of portions. To do this, we begin by performing 20 * 2 = 40 portions after the first halving. Next, we take this portion number and double it again, performing 40 * 2 = 80 portions after the second halving. Lastly, we divide this portion number by the number of portions each person will be served, performing 80 / 8 = 10 people served.
The question and answer:
Question and answer: Donna is catering for a party. She makes 20 sandwiches and then cuts them in half, before cutting them in half again. She then gives everyone 8 portions. How many people can she feed?
The answer is 10

Step-by-step reasoning process: Four long - sleeved jerseys cost $15 x 4 = $60. So the striped jerseys amount to $80 - $60 = $20. Hence, Justin bought $20 / $10 = 2 striped jerseys.
The question and answer:
Question and answer:
Justin bought some jerseys. He bought four long-sleeved ones that cost $15 each, and some striped ones that cost $10 each. How many striped jerseys did Justin buy if he spent a total of $80?
The answer is 2