There are 25 species of trees, each with a known abundances. The question is how many possible ways to randomly select one tree there are.
We should calculate the number of combinations. Combinations, because we select item/s from a collection. In this case, when we select only one item, the combination is also a permutation. From set of n objects we select r. In our case: n=25, r=1.
The equation is: n!/r!(n-r)!= 25!/1!*24!=25*24!/24!=25
There are 25 different outcomes (events).
Answer: x=9
Step-by-step explanation:
The bottom triangle that has a 40° is an isosceles triangle, therefore the other angle at the bottom right is also 40°. This leaves the top angle to be 100°.
180=40+40+x
180=80+x
x=100
Now, to find ∠2, you can tell it is a supplementary angle. Therefore, the 2 angles add up to 180°
180-100=∠2
80°=∠2
The problem states that ∠2 is 9x-1. We know that ∠2 is 80°. We can solve for x.
80=9x-1
81=9x
x=9
Answer:
A.
Step-by-step explanation:
The width is 18.
step by step:
1. 2 lengths are 20 which is 20+20 that's 40.
2. 76-40= 36
3. Two widths are 36 cm.
4. so do 36÷2 and that equals 18
