[hide=D stands for Dedekind, Z stands for Zermelo]they had two problem sets under those two names[/hide] 


[u]Set 1[/u]


[b]D1 / Z1.[/b] What is $1 + 2 \cdot 3$?


[b]D2.[/b] What is the average of the first $9$ positive integers?


[b]D3 / Z2.[/b] A square of side length $2$ is cut into $4$ congruent squares. What is the perimeter of one of the $4$ squares?


[b]D4.[/b] Find the ratio of a circle’s circumference squared to the area of the circle.


[b]D5 / Z3.[/b] $6$ people split a bag of cookies such that they each get $21$ cookies. Kyle comes and demands his share of cookies. If the $7$ people then re-split the cookies equally, how many cookies does Kyle get?  


[u]Set 2[/u]


[b]D6.[/b] How many prime numbers are perfect squares?


[b]D7.[/b] Josh has an unfair $4$-sided die numbered $1$ through $4$. The probability it lands on an even number is twice the probability it lands on an odd number. What is the probability it lands on either $1$ or $3$?


[b]D8.[/b] If Alice consumes $1000$ calories every day and burns $500$ every night, how many days will it take for her to first reach a net gain of $5000$ calories?


[b]D9 / Z4.[/b] Blobby flips $4$ coins. What is the probability he sees at least one heads and one tails?


[b]D10.[/b] Lillian has $n$ jars and $48$ marbles. If George steals one jar from Lillian, she can fill each jar with $8$ marbles. If George steals $3$ jars, Lillian can fill each jar to maximum capacity. How many marbles can each jar fill?


[u]Set 3[/u]


[b]D11 / Z6.[/b] How many perfect squares less than $100$ are odd?


[b]D12.[/b] Jash and Nash wash cars for cash. Jash gets $\$6$ for each car, while Nash gets $\$11$ per car. If Nash has earned $\$1$ more than Jash, what is the least amount of money that Nash could have earned?


[b]D13 / Z5.[/b] The product of $10$ consecutive positive integers ends in $3$ zeros. What is the minimum possible value of the smallest of the $10$ integers?


[b]D14 / Z7.[/b] Guuce continually rolls a fair $6$-sided dice until he rolls a $1$ or a $6$. He wins if he rolls a $6$, and loses if he rolls a $1$. What is the probability that Guuce wins?


[b]D15 / Z8.[/b] The perimeter and area of a square with integer side lengths are both three digit integers. How many possible values are there for the side length of the square?


PS. You should use hide for answers. D.16-30/Z.9-14, 17, 26-30 problems have been collected [url=https://artofproblemsolving.com/community/c3h2916250p26045695]here [/url]and Z.15-25  [url=https://artofproblemsolving.com/community/c3h2916258p26045774]here[/url]. Collected [url=https://artofproblemsolving.com/community/c5h2760506p24143309]here[/url].
To solve the problem, we need to determine the smallest integer \( n \) such that the product of \( n, n+1, n+2, \ldots, n+9 \) ends in three zeros. This means the product must be divisible by \( 10^3 = 1000 \), which requires at least three factors of 2 and three factors of 5 in the prime factorization of the product.

1. **Factors of 5:**
   - In any set of 10 consecutive integers, there will be exactly two multiples of 5. For example, in the set \( \{16, 17, 18, 19, 20, 21, 22, 23, 24, 25\} \), the multiples of 5 are 20 and 25.
   - To have three factors of 5, one of these multiples must be a multiple of \( 25 \) (since \( 25 = 5^2 \) contributes two factors of 5).

2. **Factors of 2:**
   - In any set of 10 consecutive integers, there will be more than enough factors of 2 to meet the requirement of three factors of 2. For example, in the set \( \{16, 17, 18, 19, 20, 21, 22, 23, 24, 25\} \), the multiples of 2 are 16, 18, 20, 22, and 24.

3. **Finding the smallest \( n \):**
   - We need to find the smallest \( n \) such that \( n, n+1, n+2, \ldots, n+9 \) contains at least three factors of 5.
   - The smallest \( n \) that satisfies this condition is when \( n = 16 \). This is because the set \( \{16, 17, 18, 19, 20, 21, 22, 23, 24, 25\} \) contains the numbers 20 and 25, which provide the necessary three factors of 5 (20 contributes one factor of 5, and 25 contributes two factors of 5).

Therefore, the minimum possible value of the smallest of the 10 integers is \( \boxed{16} \).