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question:The average marks of 30 students in a class is 100. A student's mark is wrongly noted as a certain value instead of 10. The correct average marks is 98. What was the wrongly noted mark of the student?
answer:Let's denote the wrongly noted mark as x. The sum of the marks of all 30 students with the wrong mark is: 30 * 100 = 3000 If we correct the student's mark from x to 10, the new sum of the marks will be: 3000 - x + 10 The correct average marks for the 30 students is 98, so the correct sum of the marks should be: 30 * 98 = 2940 Now we can set up the equation: 3000 - x + 10 = 2940 Solving for x: 3010 - x = 2940 x = 3010 - 2940 x = 70 The wrongly noted mark of the student was boxed{70} .
question:Multiply the first eight positive composite integers, add the first prime number to this product, then divide by the product of the next eight positive composite integers after adding the second prime number to it. Express your answer as a common fraction.
answer:The first eight positive composite numbers are 4, 6, 8, 9, 10, 12, 14, 15. The product of these numbers is ( P_1 = 4 cdot 6 cdot 8 cdot 9 cdot 10 cdot 12 cdot 14 cdot 15 ). The next eight positive composite numbers are 16, 18, 20, 21, 22, 24, 25, 26. The product of these numbers is ( P_2 = 16 cdot 18 cdot 20 cdot 21 cdot 22 cdot 24 cdot 25 cdot 26 ). The first prime number is 2 and the second prime number is 3. The modified products are: [ P_1 + 2 = 4 cdot 6 cdot 8 cdot 9 cdot 10 cdot 12 cdot 14 cdot 15 + 2 ] [ P_2 + 3 = 16 cdot 18 cdot 20 cdot 21 cdot 22 cdot 24 cdot 25 cdot 26 + 3 ] Thus, the modified quotient is: [ frac{P_1 + 2}{P_2 + 3} = frac{4 cdot 6 cdot 8 cdot 9 cdot 10 cdot 12 cdot 14 cdot 15 + 2}{16 cdot 18 cdot 20 cdot 21 cdot 22 cdot 24 cdot 25 cdot 26 + 3} ] Performing the exact calculation of these products is complex and typically not feasible without computational aid, but the expression is valid and would yield a unique fraction upon computation. Conclusion: The result of the division of these modified products is a unique fraction, represented by: [ boxed{frac{4 cdot 6 cdot 8 cdot 9 cdot 10 cdot 12 cdot 14 cdot 15 + 2}{16 cdot 18 cdot 20 cdot 21 cdot 22 cdot 24 cdot 25 cdot 26 + 3}} ]
question:Find the number of all Young diagrams with weight s for: a) s=4 b) s=5 c) s=6 d) s=7.
answer:To determine the number of Young tableaux of a given weight ( s ), we need to list all possible ways to partition ( s ) into sums of natural numbers in a non-decreasing order. Let's break down each case step-by-step. a) For ( s = 4 ): We consider all partitions of ( 4 ): 1. ( 4 ) = ( 4 ) 2. ( 4 ) = ( 3 + 1 ) 3. ( 4 ) = ( 2 + 2 ) 4. ( 4 ) = ( 2 + 1 + 1 ) 5. ( 4 ) = ( 1 + 1 + 1 + 1 ) There are a total of 5 partitions. b) For ( s = 5 ): We consider all partitions of ( 5 ): 1. ( 5 ) = ( 5 ) 2. ( 5 ) = ( 4 + 1 ) 3. ( 5 ) = ( 3 + 2 ) 4. ( 5 ) = ( 3 + 1 + 1 ) 5. ( 5 ) = ( 2 + 2 + 1 ) 6. ( 5 ) = ( 2 + 1 + 1 + 1 ) 7. ( 5 ) = ( 1 + 1 + 1 + 1 + 1 ) There are a total of 7 partitions. c) For ( s = 6 ): We consider all partitions of ( 6 ): 1. ( 6 ) = ( 6 ) 2. ( 6 ) = ( 5 + 1 ) 3. ( 6 ) = ( 4 + 2 ) 4. ( 6 ) = ( 4 + 1 + 1 ) 5. ( 6 ) = ( 3 + 3 ) 6. ( 6 ) = ( 3 + 2 + 1 ) 7. ( 6 ) = ( 3 + 1 + 1 + 1 ) 8. ( 6 ) = ( 2 + 2 + 2 ) 9. ( 6 ) = ( 2 + 2 + 1 + 1 ) 10. ( 6 ) = ( 2 + 1 + 1 + 1 + 1 ) 11. ( 6 ) = ( 1 + 1 + 1 + 1 + 1 + 1 ) There are a total of 11 partitions. d) For ( s = 7 ): We consider all partitions of ( 7 ): 1. ( 7 ) = ( 7 ) 2. ( 7 ) = ( 6 + 1 ) 3. ( 7 ) = ( 5 + 2 ) 4. ( 7 ) = ( 5 + 1 + 1 ) 5. ( 7 ) = ( 4 + 3 ) 6. ( 7 ) = ( 4 + 2 + 1 ) 7. ( 7 ) = ( 4 + 1 + 1 + 1 ) 8. ( 7 ) = ( 3 + 3 + 1 ) 9. ( 7 ) = ( 3 + 2 + 2 ) 10. ( 7 ) = ( 3 + 2 + 1 + 1 ) 11. ( 7 ) = ( 3 + 1 + 1 + 1 + 1 ) 12. ( 7 ) = ( 2 + 2 + 2 + 1 ) 13. ( 7 ) = ( 2 + 2 + 1 + 1 + 1 ) 14. ( 7 ) = ( 2 + 1 + 1 + 1 + 1 + 1 ) 15. ( 7 ) = ( 1 + 1 + 1 + 1 + 1 + 1 + 1 ) There are a total of 15 partitions. # Conclusion: - Number of Young tableaux for ( s = 4 ): ( boxed{5} ) - Number of Young tableaux for ( s = 5 ): ( boxed{7} ) - Number of Young tableaux for ( s = 6 ): ( boxed{11} ) - Number of Young tableaux for ( s = 7 ): ( boxed{15} )
question:Given the function f(x) = |x4|, (Ⅰ) If f(x) leq 2, find the range of x; (Ⅱ) Under the condition of (Ⅰ), find the maximum value of g(x) = 2sqrt{|x2|} + sqrt{|x6|}.
answer:Solution: (Ⅰ) From the given condition, |x-4| leq 2, which implies -2 leq x-4 leq 2, thus 2 leq x leq 6. Therefore, the range of x is boxed{[2, 6]}. (Ⅱ) Given 2 leq x leq 6, we have g(x) = 2sqrt{x-2} + sqrt{6-x}. By the Cauchy-Schwarz inequality, we get g(x) leq sqrt{(4+1)(x-2+6-x)} = 2sqrt{5}. The equality holds if and only if frac{sqrt{x-2}}{2} = frac{sqrt{6-x}}{1}, which happens when x = frac{26}{5}. Therefore, the maximum value of g(x) is boxed{2sqrt{5}}.