In a class of 29 students, 20 have a brother and 8 have a sister. There are 3 students who do not have any siblings. What is the probability that a student chosen randomly from the class is an only child?

1/4 = 0.25 = 25%

Step-by-step explanation:

Let x be the number of students having both brother and sister.

Brother only is 9-x

Sister only is 16-x

Brother only + sister only + both + neither = 28

(9-x) + (16-x) + x + 7 = 28

32 - x = 28

x = 4

The probability per the diagram is 4/16 = 1/4

Per definition of conditional probability:

prob( brother | sister) = prob ( brother AND sister) / prob ( sister)

            = 4/16 = 1/4

1/4 = 0.25 = 25%

step-by-step explanation:

you divide the denominator by the numerator on both sides and if the quotients are equal then the fractions are equivalent

the length of o'p' is .

step-by-step explanation:

it is given that the quadrilateral m'n'o'p' is the image of quadrilateral mnop after dilation.

the center of dilation is origin and the scale factor is 1.5.

in dilation the image and preimge are similar figures. it means the sides of image and preimage are proportional.

the scale factor is defined as

the scale factor is 1.5.

multiply both sides by op.

note: if the value of op is given, then multiply the value of op with 1.5 to get the length of side o'p'.

therefore length of o'p' is .