Answer: 720 ways
Step-by-step explanation:
Given
A train has 1 main engine and remaining 6 train cars
If the engine is always in the front the remaining train cars can be arranged is

Answer:
The density of the object is
grams per cubic centimeter. (Rounded off to 4th decimal)
Step-by-step explanation:
Density = [Mass/Volume]
Here we have been given the dimensions of the object.
Volume = Height * Width * Length
Volume = 
=
Now we can substitute the Mass and the Volume to the density equation.
Density = [Mass/Volume]
=
=
grams per cubic centimeter. (Rounded off to 4th decimal)
Answer:
7 square units
Step-by-step explanation:
Two of the points are on the horizontal line y = -3, so it is convenient to call that the "base" of the triangle. The length of the base is the difference in the x-coordinates of its end points:
b = 3 -(-4) = 7
The height is measured perpendicular to the base, so is the vertical distance from the line y=-3 to the third point. That distance is the difference between -3 and the y-coordinate of point A:
-3 -(-5) = 2
The triangle has a base of length 7 and a height of 2. Its area is ...
A = 1/2bh
A = 1/2(7)(2) = 7 . . . . square units
Answer:
for the first card selected, just multiply the number of cards of that kind over the total amount (30) by the new number of cards of that kind over the new total amount (29)
sample space is 10+6+9+5=30
7. 10/30*9/29=0.103
8. 6/30*5/29
9. 9/30*6/29
10. 5/30*9/29
11. 21/30*20/29
12. 19/30*18/29
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Define x:
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Let x be the number of students in the second class:
⇒second class = x
There are 3 more students in the first class than in the second class:
⇒first class = x + 3
There are 2 more students in the third class than in the second class:
⇒third class = x + 2
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Expression for each class:
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First class = x + 3
Second class = x
Third class = x + 2
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Expression for total number of students:
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Total = x + 3 + x + x + 2
Total = 3x + 5
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Find x:
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There are 80 students in total, so
3x + 5 = 80
3x = 75
x = 25
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Find the number of students in each class:
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First class = x + 3 = 25 + 3 = 28
Second class = x = 25
Third class = x + 2 = 25 + 2 = 27
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Answer: There are 25 students in the second class.
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