Explanation:
All of the points must be contained within a circle that will circumscribe an equilateral triangle of area 1. (We refer to this as the inscribed triangle.) Any points on the circle that do not form an equilateral triangle will form a triangle with an area less than 1. Likewise for any points within the circle.
The circle can be circumscribed by an equilateral triangle whose side length is double that of the inscribed triangle. Since the side length is double, the circumscribing triangle will have an area 2² = 4 times that of the inscribed triangle.
The inscribed triangle has an area of 1, so the circumscribing triangle must have an area of 4.
Answer: The correct number of balls is (b) 4.
Step-by-step explanation: Given that a single winner is to be chosen in a random draw designed for 210 participants. Also, there is an equal probability of winning for each participant.
We are using 10 balls, numbered through 0 to 9. We are to find the number of balls which needs to be picked up, regardless of order, so that each of the 210 participants can be assigned a unique set of numbers.
Let 'r' represents the number of balls to be picked up.
Since we are choosing from 10 balls, so we must have
The value of 'r' can be any one of 0, 1, 2, . . , 10.
Now,
if r = 1, then
If r = 2, then
If r = 3, then
If r = 4, then
Therefore, we need to pick 4 balls so that each participant can be assigned a unique set of numbers.
Thus, (b) is the correct option.
Answer:
the numbers are 10.6 and 10.2
Answer:
18 = 4(3)+6
12 + 6
Step-by-step explanation:
the answer is 18 = 4(3)+6
because y is 18
Let the slower train's velocity be x-21
Let the faster train's velocity be x
We know that the approach speed is the sum of both speeds, so x+x -21= 2x-21.
The approach rate is given by Distance/time = 471/3 = 157mpH
x+x-21=157
2x=157+21
2x=178
x=89mph
The slower train is travelling 89-21 = 68mph
The faster train is travelling 89mph.
