A box contains 9 balls written B, E,R, N,H, E,A, R,T. Two balls are drawn at random without replacement. what is the probability of getting both balls written with R ?​

How many balls have “R” written on them initially? We can see this is 2.

How many balls are there initially? This is 9.

As a result, the probability of initially drawing a ball with an R on it is 2/9, as out of the 9 possible draws we could make, 2 of them result in a ball with R on it.

How many balls have “R” written on them now? We can see this is 1, since we just drew one ball with R on it and didn’t replace.

How many balls are there in total right now? This is 8, because we took away one.

As a result, the probability of drawing a ball with an R on it after having already done so is 1/8, as out of the 8 possible draws we could make, 1 results in a ball with R on it.

We then multiply these two values (2/9)*(1/8) = 2/72, which is our probability.

Another way to think about this is that there are 72 possible combinations of balls that we could draw, counting each ball uniquely. This is because of our denominator, since 8*9=72. Out of those 72 outcomes that could possibly happen, 2 outcomes will result in both balls being written with R.

Step-by-step explanation:

(f - g)(x) = 5x^3 - 3

step-by-step explanation:

rearrange these functions vertically, with like terms in separate columns:

f(x) = 5x^3 - 2

g(x) =         +1

now subtract, column by column:

(f - g)(x) = 5x^3 - 3

when functions are first introduced, you will probably have some simplistic "functions" and relations to deal with, usually being just sets of points. these won't be terribly useful or interesting functions and relations, but your text wants you to get the idea of what the domain and range of a function are. small sets of points are generally the simplest sorts of relations, so your book starts with those.

step-by-step explanation:

state the domain and range of the following relation. is the relation a function?

{(2, –3), (4, 6), (3, –1), (6, 6), (2, 3)}

the above list of points, being a relationship between certain x's and certain y's, is a relation. the domain is all the x-values, and the range is all the y-values. to give the domain and the range, i just list the values without duplication:

domain: {2, 3, 4, 6}

range: {–3, –1, 3, 6}

(it is customary to list these values in numerical order, but it is not required. sets are called "unordered lists", so you can list the numbers in any order you feel like. just don't duplicate: technically, repetitions are okay in sets, but most instructors would count off for this.)

while the given set does indeed represent a relation (because x's and y's are being related to each other), the set they gave me contains two points with the same x-value: (2, –3) and (2, 3). since x = 2 gives me two possible destinations (that is, two possible y-values), then this relation is not a function.

note that all i had to do to check whether the relation was a function was to look for duplicate x-values. if you find any duplicate x-values, then the different y-values mean that you do not have a function. remember: for a relation to be a function, each x-value has to go to one, and only one, y-value.

state the domain and range of the following relation. is the relation a function?

{(–3, 5), (–2, 5), (–1, 5), (0, 5), (1, 5), (2, 5)}

i'll just list the x-values for the domain and the y-values for the range: