Home
Class 12
MATHS
STATEMENT -1: The tens digit of 1! + 2! ...

STATEMENT -1: The tens digit of 1! + 2! + 3! + 4! + 5! +........... + 50! is 1.
STATEMENT-2 : The sum of divisors of `2^(4)3^(5)5^(2)7^(3)` is `2^(5).3^(6).5^(3).7^(4) - 2.3.5.7.`

A

Statement-1 is true ,statement -2 is true , statement -2 is a correct explanation for statement -3

B

Statement -1 is true , statement -2 is true , statement -2 is NOT a correct explanation for statement -3

C

Statement -1 is true , statement -2 is false

D

Statement -1 is false , statement -2 is true

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given statements, we will analyze each statement step by step. ### Statement 1: The tens digit of \(1! + 2! + 3! + 4! + 5! + \ldots + 50!\) is 1. 1. **Calculate Factorials**: - \(1! = 1\) - \(2! = 2\) - \(3! = 6\) - \(4! = 24\) - \(5! = 120\) - \(6! = 720\) - \(7! = 5040\) - \(8! = 40320\) - \(9! = 362880\) - \(10! = 3628800\) (and all higher factorials will end with at least two zeros) 2. **Sum the Factorials**: - From \(1!\) to \(9!\), we sum: \[ 1 + 2 + 6 + 24 + 120 + 720 + 5040 + 40320 + 362880 = 403791 \] - From \(10!\) to \(50!\), since they all end with at least two zeros, they do not contribute to the tens digit. 3. **Identify the Tens Digit**: - The sum \(403791\) has a tens digit of \(9\). 4. **Conclusion for Statement 1**: - The tens digit of \(1! + 2! + 3! + \ldots + 50!\) is \(9\), not \(1\). Therefore, Statement 1 is **False**. ### Statement 2: The sum of divisors of \(2^4 \cdot 3^5 \cdot 5^2 \cdot 7^3\) is \(2^5 \cdot 3^6 \cdot 5^3 \cdot 7^4 - 2 \cdot 3 \cdot 5 \cdot 7\). 1. **Sum of Divisors Formula**: - The sum of divisors for \(n = p_1^{k_1} \cdot p_2^{k_2} \cdots p_m^{k_m}\) is given by: \[ \sigma(n) = (1 + p_1 + p_1^2 + \ldots + p_1^{k_1})(1 + p_2 + \ldots + p_2^{k_2}) \cdots (1 + p_m + \ldots + p_m^{k_m}) \] 2. **Apply the Formula**: - For \(2^4\): \[ 1 + 2 + 4 + 8 + 16 = 31 \] - For \(3^5\): \[ 1 + 3 + 9 + 27 + 81 + 243 = 364 \] - For \(5^2\): \[ 1 + 5 + 25 = 31 \] - For \(7^3\): \[ 1 + 7 + 49 + 343 = 400 \] 3. **Calculate the Total Sum of Divisors**: - Now, multiply these results: \[ \sigma(n) = 31 \cdot 364 \cdot 31 \cdot 400 \] 4. **Check the Given Expression**: - The expression given in Statement 2 is: \[ 2^5 \cdot 3^6 \cdot 5^3 \cdot 7^4 - 2 \cdot 3 \cdot 5 \cdot 7 \] - We need to verify if this matches with our calculated sum of divisors. 5. **Conclusion for Statement 2**: - After calculating and simplifying, we find that the expression does not hold true. Therefore, Statement 2 is also **False**. ### Final Conclusion: - Both Statement 1 and Statement 2 are **False**.
Promotional Banner

Topper's Solved these Questions

  • PERMUTATIONS AND COMBINATIONS

    AAKASH INSTITUTE|Exercise Assignment Section F (Matrix-Match Type Questions)|6 Videos
  • PERMUTATIONS AND COMBINATIONS

    AAKASH INSTITUTE|Exercise Assignment Section-G (Integer Answer type Questions)|5 Videos
  • PERMUTATIONS AND COMBINATIONS

    AAKASH INSTITUTE|Exercise Assignment Section D Linked Comprehension Type Questions|12 Videos
  • MATRICES

    AAKASH INSTITUTE|Exercise Assignment (Section - J) Aakash Challengers Questions|3 Videos
  • PRINCIPLE OF MATHEMATICAL

    AAKASH INSTITUTE|Exercise Section-D:(Assertion-Reason Type Questions)|12 Videos

Similar Questions

Explore conceptually related problems

The sum of the divisors of 2^(5).3^(7).5^(3).7^(2), is

The sum to n terms of [(1)/(1.3)+(2)/(13.5)+(3)/(1.3.5.7)+(4)/(1.3.5.7.9)+…………]

The value of ((2/5)^(3)xx(1/7)^(3))/((2/5)^(2)xx(1/7)^(4)) is

((3^(-1)7^(2))/(3^(3)7^(-4)))/((3^(3)7^(-5))/(2^(-2)7^(3)))

Find the sum of the infinite series (1.3)/(2)+(3.5)/(2^(2))+(5.7)/(2^(3))+(7.9)/(2^(4))+......oo

What is the value of [(6.5)^(3)+(4.7)^(3)]div[(6.5)^(2)-6.5xx4.7+(4.7)^(2)]?

The sum of the series (5)/(1.2.3)+(7)/(3.4.5)+(9)/(5.6.7)+.... is equal to