Here are the solutions to the Brain Teasers worksheet.
1. The Elevator Riddle
*Reasoning:* This is a classic riddle. If the person can reach the 7th floor button but not the 10th, they are likely too short to reach higher buttons. On rainy days, they have an umbrella, which allows them to push the higher button.
*Answer:* The person is a child (or a very short person) who cannot reach the button for the 10th floor. They use their umbrella to push it on rainy days.
2. The Family Math
*Reasoning:* Let's break down the family members mentioned:
- "Two fathers and two sons" usually refers to three people: A Grandfather, a Father, and a Son. (The Father is both a son to the Grandfather and a father to the Son). So, that is
3 men.
- "One mother and one daughter": We already have the Son (who is male). We need a female pair. This adds a Mother and her Daughter. That is
2 females.
- Total people = 3 men + 2 females = 5 people.
- The problem states each person ate one banana.
*Answer:* 5 bananas were eaten.
3. Coins for a Dollar
*Reasoning:* To get the *most* coins, you want to use the coins with the smallest value (pennies) as much as possible. However, you must be able to make exactly $1.00.
- If you have 100 pennies, that is exactly $1.00. But can you have *more* than 100 coins? No, because pennies are the smallest unit.
- Wait, let's look at combinations. If you use dimes, nickels, or quarters, you reduce the total number of coins because those coins are worth more. For example, 4 quarters is only 4 coins. 10 dimes is 10 coins.
- Therefore, using all pennies gives the highest count.
*Answer:* 100 coins (100 pennies).
4. Socks in the Dark
*Reasoning:* You have black socks and white socks. You want a matching pair (two of the same color).
- Pick 1 sock: It could be Black or White.
- Pick 2 socks: You might have one Black and one White. They don't match.
- Pick 3 socks: The third sock *must* be either Black or White. Since you already have one of each from the first two picks, this third sock will match one of them.
*Answer:* 3 socks.
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Final Answer:
1. The person is a child (or short adult) who uses an umbrella to reach the high button.
2. 5 bananas
3. 100 coins
4. 3 socks
Parent Tip: Review the logic above to help your child master the concept of middle school brain teasers worksheet.
