Answer:
see explanation
Step-by-step explanation:
Given the 2 equations
5x + y = 21 → (1)
x - 3y = 9 → (2)
Multiply (1) by 3 and add the result to (2) to eliminate y term
15x + 3y = 63 → (3)
Add (2) and (3) term by term
(x + 15x) + )- 3y + 3y) = (9 + 63)
16x = 72 ( divide both sides by 16 )
x = 4.5
Substitute x = 4.5 into (1) for corresponding value of y
22.5 + y = 21 ( subtract 22.5 from both sides )
y = - 1.5
Solution is (4.5, - 1.5 )
Definition: A histogram visualises the distribution of data over a continuous interval or certain time period. Each bar in a histogram represents the tabulated frequency at each interval.
According to the given histogram,
0-20 years occur 15 times,
21-40 years occur 40 times,
41-60 years occur 40 times,
61-80 years occur 15 times.
This shows that the data is symmetrical and the majority of the attendees were between the ages of 21 and 60 (40 times).
Answer: correct choice is B.
Answer: 360 / 24 = 15
Step-by-step explanation :
Since the sum of the exterior angles is always 360 degrees, if you divide 360 degrees by 24 degrees you get 15 which is the number of equal exterior angles and therefore 15 vertices and sides to the polygon.
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).
