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question:Calculate: (frac{1}{2})^{2}+(pi 3.14)^{0}+4cos 45^{circ}|1sqrt{2}|.
answer:To solve the given expression step-by-step, we start with the original expression: [(-frac{1}{2})^{-2}+(pi -3.14)^{0}+4cos 45^{circ}-|1-sqrt{2}|] First, we simplify each term individually: 1. (-frac{1}{2})^{-2} simplifies to 4 because raising a fraction to the power of -2 inverts the fraction and squares it, thus (-frac{1}{2})^{-2} = left(frac{1}{-frac{1}{2}}right)^2 = (-2)^2 = 4. 2. (pi -3.14)^{0} simplifies to 1 because any non-zero number raised to the power of 0 is 1. 3. 4cos 45^{circ} simplifies to 4times frac{sqrt{2}}{2} because cos 45^{circ} = frac{sqrt{2}}{2}. Therefore, 4cos 45^{circ} = 4times frac{sqrt{2}}{2} = 2sqrt{2}. 4. |1-sqrt{2}| simplifies to |sqrt{2}-1| because 1-sqrt{2} is negative, and taking the absolute value flips the sign, resulting in sqrt{2}-1. Putting it all together, we have: [4 + 1 + 2sqrt{2} - (sqrt{2}-1)] [= 4 + 1 + 2sqrt{2} - sqrt{2} + 1] [= 4 + 1 + sqrt{2} + 1] [= 6 + sqrt{2}] Therefore, the final answer is boxed{sqrt{2} + 6}.
question:Miss Quick needs 15 minutes to eat a pound of cereal, Mr. Fat needs 20 minutes, and Mr. Thin needs 30 minutes. If all three eat together, how long does it take for them to finish off four pounds of cereal? Express your answer in minutes.
answer:Miss Quick eats cereal at a rate of frac{1}{15} pound per minute, Mr. Fat eats at frac{1}{20} pound per minute, and Mr. Thin eats at frac{1}{30} pound per minute. Together, they eat at a combined rate of frac{1}{15} + frac{1}{20} + frac{1}{30}. To find the combined rate, find a common denominator for the fractions: [ frac{1}{15}=frac{4}{60}, , frac{1}{20}=frac{3}{60}, , frac{1}{30}=frac{2}{60} ] Therefore, the combined rate is: [ frac{4}{60}+frac{3}{60}+frac{2}{60}=frac{9}{60}=frac{3}{20} text{ pounds per minute} ] At this rate, to eat four pounds of cereal: [ frac{4}{frac{3}{20}} = frac{4 times 20}{3} = frac{80}{3} approx 26.67 text{ minutes} ] Therefore, it will take them boxed{frac{80}{3}} minutes (or approximately 26.67 minutes) to eat 4 pounds of cereal.
question:Leonid has a white checkered rectangle. First, he painted gray all the columns every other one, starting from the leftmost one, and then he painted gray all the rows every other one, starting from the topmost one. All the cells adjacent to the boundary of the rectangle have ended up being painted. How many painted cells could there be in the rectangle if there are 74 white cells left? Indicate all possible options. An example of a coloring of a 5 times 7 rectangle is shown below.
answer:1. **Understanding the problem requirements**: - Leonid paints a rectangular grid by coloring every other column starting from the first column, and then colors every other row starting from the first row. - The problem is to find the possible number of painted cells given that 74 white cells remain. 2. **Examining the structure of the grid**: - Denote the number of rows by (2k+1) and the number of columns by (2l+1), both must be odd numbers. This is because he colors every other column and row starting from the first, ensuring that every even-numbered row and column remain unpainted. - Each white cell must lie in a position where both its row number and column number are even. 3. **Formulating the relationship**: - The number of unpainted (white) cells after grid is colored is given by: [ text{Number of unpainted cells} = k times l = 74 ] - Therefore, we need (k times l = 74). 4. **Finding possible values for (k) and (l)**: - The pairs ((k, l)) that satisfy (k times l = 74) are ((1, 74)) and ((2, 37)), because these are only factors of 74: [ k = 1, quad l = 74 quad text{(since (1 times 74 = 74))} ] [ k = 2, quad l = 37 quad text{(since (2 times 37 = 74))} ] 5. **Calculating the total number of cells and painted cells**: - The total number of cells in the rectangle is ((2k+1) times (2l+1)). - The number of painted cells is then given by subtracting the number of white cells from the total number of cells: [ text{Number of painted cells} = (2k+1) times (2l+1) - k times l ] 6. **Substituting the values**: - For (k = 1) and (l = 74): [ text{Total cells} = (2 times 1 + 1) times (2 times 74 + 1) = 3 times 149 = 447 ] [ text{Painted cells} = 447 - 74 = 373 ] - For (k = 2) and (l = 37): [ text{Total cells} = (2 times 2 + 1) times (2 times 37 + 1) = 5 times 75 = 375 ] [ text{Painted cells} = 375 - 74 = 301 ] Hence, the possible solutions are (373) and (301). # Conclusion: [ boxed{373 text{ or } 301} ]
question:Katy participated in a summer reading program at her local library. She read 8 books in June, twice as many in July and three fewer in August than she did in July. How many books did Katy read during the summer?
answer:In June, Katy read 8 books. In July, she read twice as many as in June, so she read 8 * 2 = 16 books. In August, she read three fewer than in July, so she read 16 - 3 = 13 books. To find the total number of books she read during the summer, we add the books from each month together: 8 (June) + 16 (July) + 13 (August) = 37 books. Katy read boxed{37} books during the summer.