Question: Grace is filling her pool in the backyard with a hose that sprays 50 gallons/hour. She waited for 3 hours but the pool wasn't full, so she decides to add another hose that sprays 70 gallons/hour, and after 2 more hours the pool is full. How much water can Grace’s pool contain?
Answer with step-by-step thinking: In the first 3 hours the pool gets 50 gallons / hour x 3 hours = 150 gallons. With the addition of the other hose, the pool was filling with a rate of 50 gallons / hour + 70 gallons / hour = 120 gallons / hour. In the next 2 hours with both hoses the pool gets 120 gallons / hour x 2 hours = 240 gallons. The pool's total capacity is 240 gallons + 150 gallons = 390 gallons.
So the answer is 390.


Question: Mark constructed a deck that was 30 feet by 40 feet. It cost $3 per square foot. He then paid an extra $1 per square foot for sealant. How much did he pay?
Answer with step-by-step thinking: The deck is 30 * 40 = 1200 square feet. He pays 3 + 1 = $4 per square foot. So he paid 1200 * 4 = $4800.
So the answer is 4800.


Question: Leo's assignment was divided into three parts. He finished the first part of his assignment in 25 minutes. It took him twice as long to finish the second part. If he was able to finish his assignment in 2 hours, how many minutes did Leo finish the third part of the assignment?
Answer with step-by-step thinking:
It took Leo 25 x 2 = 50 minutes to finish the second part of the assignment. Leo finished the first and second parts of the assignment in 25 + 50 = 75 minutes. He finished the entire assignment in 60 x 2 = 120 minutes. Therefore, it took Leo 120 - 75 = 45 minutes to finish the third part of the assignment.
So the answer is 45.