Q: A survey conducted by the school showed that only 20% of the 800 parents agree to a tuition fee increase. How many parents disagree with the tuition fee increase?
A: There were 800 x 20 / 100 = 160 parents who agreed to the tuition fee increase. So, there were 800 - 160 = 640 parents who disagreed. The answer is 640.

Q: Brad wanted to set up a lemonade stand to earn some money. Every gallon of lemonade would yield 16 glasses. He figured it would cost him $3.50 to make every gallon of lemonade. He made 2 gallons to sell and decided he would sell each glass for $1.00 He drank 5 glasses while sitting in his stand. He sold all but 6 glasses of lemonade. How much net profit did Brad earn?
A: He made 2 gallons and each gallon had 16 glasses so 2 * 16 = 32 glasses. He drank 5 glasses and had 6 left over which means he would not earn money on 5 + 6 = 11 glasses. The total revenue would come from 32 - 11 = 21 glasses. Each gallon cost $3.50 to make so the total cost was 2 * 3.50 = $7.00. He sold 21 glasses at $1.00 per glass for a total of 1 * 21 = $21.00. When you take his earnings of $21.00 and subtract the cost of $7.00 his total net profit was 21 - 7 = $14.00. The answer is 14.

Q: Two-thirds of all the animals on my street are cats and the rest are dogs. If there are 300 animals on the street, what's the total number of legs of dogs that are on the street?
A:
The number of cats on the street is 2 / 3 * 300 = 200. If there are 300 animals on the street, and 200 are cats, there are 300 - 200 = 100 dogs. Since a dog has four legs, the total number of legs the 100 dogs have is 100 * 4 = 400 legs. The answer is 400.