Cast a rectangular iron block of 10 cm long, 8 cm wide and 5 cm high into a cylinder iron block of 20 cm in diameter, and calculate the height of the cylinder iron block Two decimal places are reserved for the loss result

Cast a rectangular iron block of 10 cm long, 8 cm wide and 5 cm high into a cylinder iron block of 20 cm in diameter, and calculate the height of the cylinder iron block Two decimal places are reserved for the loss result

The volume of rectangle is 10 × 8 × 5 = 400 cubic centimeter
The volume of the cylinder is bottom area × height, and the bottom area is 3.14 × (20 △ 2) 2 = 314 square centimeters
So the height is 400 △ 314 = 1.27cm

Cut a rectangular iron block 20 cm long, 8 cm wide and 10 cm high into the largest cylinder on the lathe. What do you think is the volume of the largest cylinder? What is the volume of the cut part?

8 △ 2 = 4 (CM), 3.14 × 42 × 20, = 3.14 × 16 × 20, = 1004.8 (cm3), 20 × 10 × 8-1004.8, = 1600-1004.8, = 595.2 (cm3); a: the maximum volume of this cylinder is 1004.8 cm3, and the truncated volume is 595.2 cm3

2 + 4 + 6 + 8 + 10. + 2010 =? How to use a simple method to calculate

Using the method of flashback addition (2 + 2010) + (4 + 2008) +. + (2010 + 2) = 2012 times 1005
Divide the final result by 2!

1 / 8 of a number is equal to the sum of 2 / 5 and 3 / 4. What is the number

Let this number be a, then:
a/8=2/5+3/4
a/8=8/20+15/20
a/8=23/20
a=23x8/20
a=46/5
A: the number is 46 / 5

The standard elliptic equations passing through point a (- 1, - 2) and having the same focus as the ellipse X & # 178 / 6 + Y & # 178 / 9 = 1 are?

Let X & # 178; / (6 + U) + Y & # 178; / (9 + U) = 1 be the solution of two elliptic standard equations with the same focus as the ellipse X & # 178 / / 6 + Y & # 178; / (9 + U) = 1（
9+u＞0）
From passing point (- 1, - 2)
That is (- 1) & # 178; / (6 + U) + (- 2) & # 178; / (9 + U) = 1
The solution is U & # 178; + 10u + 21 = 0
The solution is u = - 3 or u = - 7
From 6 + U > 0,
That is to say, u = - 7
That is u = - 3
That is to say, the elliptic standard equation is X & # 178 / 3 + Y & # 178 / 6 = 1

1. How many ways can 2 and 3 be arranged into 3 digits? What are the rules and formulas

123 132 231 213 321 312 this is a mathematical problem. The formula is: n * (n-1) * (n-2) *... * 1, that is, n!

2X minus 2 times 3 is equal to 6?

2X minus 2 times 3 equals 6
(2x-2)*3=6
4x-6=6
4x=12
x=3

Two is a fraction

1/2 2/4 3/6 4/8 5/10 6/12 7/14

Vlookup ($c131, $B $9: $f $12, column () - 1,0), vlookup ($c131, $C $9: $f $12, column () - 2,0)
Be specific

Is the current column number - 1 or - 2
Column () is the current column number
In your formula, it means when you extract the data of columns - 1 and - 2 in the front row of column B: F

The solution equation: X / (1-24%) = 150

X/（1-24%）=150
x=150×（1-24%）
x=150×76%
x=114
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