Math Problem Statement
1x2x3x4x5x6x...x206x207x208 + 3 divided by 30, what is the remaining number?
Solution
The given expression is:
First, notice that represents the factorial of 208, denoted as . So, the expression becomes:
Now, we are interested in the remainder when is divided by 30.
Step 1: Analyze modulo 30
We know that is the product of all integers from 1 to 208. Since includes multiples of 2, 3, and 5 (which are factors of 30), it follows that is divisible by 30. Therefore:
Step 2: Consider modulo 30
Since , we can now calculate:
Thus, the remainder when is divided by 30 is 3.
Final Answer:
The remainder is 3.
Would you like any additional details or clarification?
Here are 5 related questions to consider:
- What is the definition of factorial and how is it used in combinatorics?
- How do you calculate large factorials efficiently?
- How do modular arithmetic and remainders work in division problems?
- What are the properties of divisibility rules for numbers like 30?
- What role do prime factors play in simplifying large factorials?
Tip: For large numbers, breaking the problem into smaller parts, such as focusing on the factors of the divisor, simplifies the process.
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Math Problem Analysis
Mathematical Concepts
Factorials
Modular Arithmetic
Divisibility
Formulas
n! = n × (n - 1) × (n - 2) × ... × 1
Modular Arithmetic: (a + b) mod n = ((a mod n) + (b mod n)) mod n
Theorems
Factorial Divisibility by 30: Factorials involving multiples of 2, 3, and 5 are divisible by 30
Modular Arithmetic Theorem
Suitable Grade Level
Grades 10-12