This is an arithmetic sequence, since it's pattern is +4.
n1 = 1
d = 4
n = 1 + (n-1)(4) <-------------- This is the formula for the nth term of the sequence.
Answer:
32
Step-by-step explanation:
1. If you take 12 balls, 9 could be yellow and 3 could be red. We want at least 12 of the same color, so 30 balls isn't a good minimum
2. If you take 30 balls, 9 could be yellow, 10 could be red and 11 could be green. We want at least 12 of the same color, so 30 balls isn't a good minimum.
3. If you take 31 balls, 9 could be yellow, 11 could be red and 11 could be green. We want at least 12 of the same color, so 31 balls isn't a good minimum.
4. If you take 32 balls, 9 could be yellow, 11 could be red and 12 could be green or 9 could be yellow, 12 could be red and 11 could be green or 7 could be yellow, 13 could be red and 12 could be green or 9 could be yellow, 11 could be red and 12 could be green.
We want at least 12 of the same color, and we have it from the different samples of the 4th trial.
So, 32 balls is the minimum number of balls
Step-by-step explanation:
<span>A) First function, y varies directly with x.
1) function: y = (3/4)x
2) graph: it is a straight line that passes through the origin and has slope 3/4. The slope means that the rate of change of the function is 3 units per every 4 units the x-value incresase or, what is the same 0.75 units per incresase unit of x - value.
3) real world example
A recipe of a cake instructs to use 3 cups of sugar for every 4 cups of flour. So, how much flour you need if you have 12 cups of sugar?
y = (3/4)x , so if x = 3, y = (3/4)*12 = 3*12/4 = 9.
So, given that the variation is direct you multiply the number of cups of sugar times the constant rate, 3/4, to get the number of cups of flour in relation with the given amount of sugar.
B) The second function: y varies inversely with x.
Inverse variation => y*x = constant or y = constant / x.
Tnat means that if x increase y will decrease in the same factor that x increases.
1) function: y = 12 / x
2) graph: the form of this graph is called hyperbola, it is a decreasing line from left to right. It has two asymptotes, the y-axis (x =0) and the x-axis (y = 0). That means that x and y can never be zero.
As the x-value approaches 0, the y value approaches positive or negative infinity; as the y-values approaches 0 the x-values approaches to positive or negative infinity.
If you take the positive values, the graph is a decreasing curve in the first quadrant (x and y are positive).
If you take the negative values, the graphs is a decreasing curve in the third quadrant (x and y are negative)
3) real world example.
The relatioship between velocity and time in a uniform motion.
If the distance run by an object is constant, as the velocity increases the time decreases in the same factor.
Suppse a distant of 100 km between cities A and B.
How long will it take to travel from A to B at 50 km/ h and 25 km/h ?:
100 km = velocity * time
at 50 km/h: 100 km = 50 km/h * t => t = [100 km ] / [50 km/h] = 2 hours
at 25 km/h: 100 kg = 25 km/h * t => t = [ 100 km ] / [25 km/h] = 4 hours.
C) Third case, the relationship between
x and y should is neither inverse variation nor direct variation.
Of course, there are infinite type of functions that are neither inverse variation nor direct variation: linear (that do not passe through the origin), quadratic, exponential, logarithmical, trigonometric sine, ...
1) example of function: y = 30 + 2x
2) graph: it is a straigh line with y-intercept 30 and slope 2.
3) real world example:
The cost of producing chairs consists of 30 dollars of rent for the facility plus 2 dollar to produce each chair, so the total cost y is 30 + 2x.
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