You can choose from 20 students for the first student, 19 for the second, 18 for the third, ..., 14 for the seventh student.
That gives you 20 * 19 * 18 * 17 * 16 * 15 * 14.
That number would allow you to write the students in different order. Since order here does not matter, any group with the same students in any order is the same group, you need to divide by the number of way you can order 7 items. Divide by 7 * 6 * 5 * 4 * 3 * 2 * 1
(20 * 19 * 18 * 17 * 16 * 15 * 14)/(7 * 6 * 5 * 4 * 3 * 2 * 1) = 77,520
Answer: 77,520
Answer:
The original height of the tree is 18 m.
Step-by-step explanation:
Please see attached photo for explanation.
From the diagram, we shall determine the value of 'x'. This can be obtained by using the pythagoras theory as follow:
x² = 5² + 12²
x² = 25 + 144
x² = 169
Take the square root of both side
x = √169
x = 13 m
Finally, we shall determine the original height of the tree. This can be obtained as follow.
From the question given above, the tree was broken from a height of 5 m from the ground which form a right angle triangle with x being the Hypothenus as illustrated in the diagram.
Thus, the original height of the will be the sum of 5 and x i.e
Height = 5 + x
x = 13 m
Height = 5 + 13
Height = 18 m
Therefore, the original height of the tree is 18 m.
Answer:
length = 60m
Step-by-step explanation:
let '3x' = length
let '2x' = width
3x + 3x + 2x + 2x = 200
10x = 200
x = 20
length = 3x = 3(20) = 60