By accident, 8 burned out bulbs have additionally been mixed in with 30 good ones. ken is replacing old bulbs in his house. if he selects two bulbs at random from the box of 38, what is the probability they both work?

p(both work) =
435 / 703

p(both work) =
28 / 703

p(both work) =
16 / 361

p(both work) =
169 / 256

The correct answer option is P(Both Work) =  435 / 703

Step-by-step explanation:

We are given that in a box of total 38 bulbs, 8 are the defective ones while the rest are good.

If Ken selects two bulbs at random from the box, we are to find the probability that they both work.

1st bulb: P (bulb works) =  

2nd bulb: P (bulb works) =

P (Both Work) = = 435 / 703

The correct answer is first option.   P(Both Work) =  435/703

Step-by-step explanation:

It is given that,

There are 8 burned bulbs and 30 good bulbs.

Therefore total number of bulbs = 8 + 30 = 38

To find the probability

We have to take two working bulbs from total bulbs.

Total bulbs = 38

The probability of taking two working bulbs = P(Both Work)

P(Both Work) = 30C₂/38C₂

  = (30 * 29)/(38 * 37) = 435/703

Therefore the correct answer is first option

the results from a pre-test for students for the year 2000 and the year 2010 are illustrated in the box plot. what do these results tell us about how students performed on the 29 question pre-test for the two years?

if we compare only the lowest and highest scores between the two years, we might conclude that the students in 2010 did better than the students in 2010. this conclusion seems to follow since the lowest score of 8 in 2010 is greater in value than the lowest score of 6 in 2000. also, the highest score of 28 in 2010 is greater in value than the highest score of 27 in 2000.

but the box portion of the illustration gives us more detailed information. the middle bar in each box shows us that the median score of 20 in 2000 is greater in value than the median score of 17 in 2010. further, we note that the box and whiskers divide the illustration into four pieces. each of these four pieces represents the same portion of students. so, the upper half of the students in 2000 scored in the same score range as the upper one-fourth of the students in 2010, see the illustration at a score of 20.

by considering the upper one-fourth, upper half, and upper three-fourths instead of just the lowest and highest scores, we would conclude that the students as a whole did much better in 2000 than in 2010. we would conclude that as a whole the students in 2010 are less prepared than the students in 2000.

in this section, we discuss box-and-whisker plots and the five key values used in constructing a box-and-whisker plot. the key values are called a five-number summary, which consists of the minimum, first quartile, median, third quartile, and maximum.

step-by-step explanation:

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step-by-step explanation: