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For the natural number n, the sum of the numbers is Sn, such as s2005 = 2 + 0 + 0 + 5 = 7, then S0 + S1 + S2004+S2005=?
The period of single digit 0-9 is 10, the period sum of each week is 0 + 1 +... 9 = 45, the period sum of tens is 100, the period sum of each week is 10 (0 + 1 +... 9) = 450, the period sum of hundreds is 1000, the period sum of each week is 100 (0 + 1... + 9) = 4500, and the period sum of each week is 2x450 =
RELATED INFORMATIONS
- 1. How to calculate the sum of incomplete squares of 100 natural numbers from 1 to 100?
- 2. How many squares are there in natural numbers 100 to 200?
- 3. Natural numbers m, n satisfy m + n = 1991, prove: 10 ^ m + 10 ^ n is a multiple of 11? Who knows?
- 4. M. N is a non-zero natural number, and 1 / M-1 / N = 2 / 143, M + n = () how to do
- 5. If the natural number AB satisfies 1 / A-1 / b = 1 / 182 and a: B = 7:13, what is the sum of a + B Why is this 13 / 7b-1 / b = 1 / 182 Here is (13-7) / 7b = 1 / 182 Why (13-7) / 7b = 1 / 182 The process should be very detailed,
- 6. Compare the fractions n / M and n-a / M-A (m, N, a, are all non-zero natural numbers)
- 7. Let a and B be natural numbers and satisfy 11 / A + B / 3 = 17 / 33, then a + B = ()
- 8. Let a, B, C be real numbers, and prove: A & sup2; B & sup2; + B & sup2; C & sup2; + A & sup2; C & sup2; ≥ ABC (a + B + C)
- 9. It is proved that √ A & sup2; + B & sup2; + C & sup2; / 3 ≥ a + B + C / 3 ≥ & sup3; √ ABC (where a, B, C ∈ positive real numbers, and each pair is unequal),
- 10. Step 1: take a natural number N1 = 5, calculate the square of N1 plus 1 to get A1; step 2: calculate the sum of all numbers of A1 to get N2, calculate the square of N2 plus 1 to get A2 Three steps: calculate the sum of the numbers of A2 to get N3, and add 1 to the square of N3 to get A3
- 11. The sum of all digits of natural number n is Sn, such as n = 38, Sn = 3 + 8 = 11; n = 247, Sn = 2 + 4 + 7 = 13. If n-sn = 2007 is satisfied for some natural numbers, the maximum value of n is () A. 2025B. 2023C. 2021D. 2019
- 12. Let a = {x | x = 2n + 1, n ∈ n}, B = {x | 1 ≤ x ≤ 10}, C = {x | x = 3N, n ∈ n}, find (a ∩ b) ∩ C
- 13. It is stipulated that the "H operation" of positive integer n is: ① when n is odd, H = 3N + 13; ② when n is even, H = NX1 / 2x1 / 2 Where h is odd For example, the result of number 3 after one "H operation" is 22, the result after two "H operations" is 11, and the result after three "H operations" is 46 (1) Find 257, after 257 times of "H operation" to get the result (2) If the result of "H operation" is always constant a, find the value of A I want to solve the problem
- 14. What is the answer to an h-operation with odd number 3N = 13 and even number * 1 / 2 until odd number 257?
- 15. It is stipulated that an operation on positive integer n, whose rule is: F (n) = 3N + 1 (n is odd) 2n − 1 (n is even), then f (3)=______ ，f[f（1）]=______ ．
- 16. What are the number of items and times in a ^ 3-A ^ 2b-b ^ 3, 3N ^ 4-2n ^ 2 + 1?
- 17. If the 2nth power of x = 3, find the value of the fourth power of (- 1 / 3 x to the 3nth power) / [the 2nth power of 4 (X & # 179;)]
- 18. 3 × 9 ^ n × 27 ^ n-1 = 3 x 3 ^ 2n x 3 ^ (3n-3)
- 19. Given 3 ^ m = 2, 3N ^ = 4, find the value of 9 ^ m + 1-2n
- 20. Prove n + (n + 1) + (n + 2)... + 2n = 3N (n + 1) / 2 by induction