Die waarskynlikheid dat ‘n sekere deur gesluit is, is 0.6. Die sleutel vir die deur is een van vyf ongeïdentifiseerde sleutels op ‘n sleutelhouer. U kies ewekansig twee sleutels van die sleutelhouer voor u die deur nader. Die waarskynlikheid dat u die deur kan oopmaak sonder om vir nog sleutel terug te gaan is / The probability that a certain door is locked is 0.6. The key to the door is one of five unidentified keys hanging on a key chain. You randomly select two keys from the key holder before approaching the door. The probability that you can open the door without returning for another key is

‘n Houer bevat 25 onderdele waarvan drie defektief en 22 nie-defektief is. Indien twee onderdele ewekansig en sonder terugplasing gekies word, is die waarskynlikheid dat slegs een defektief is  / A box contains 25 parts, of which three are defective and 22 are non-defective. If two parts are selected without replacement, the probability that exactly one part is defective, is

Gebeurtenisse A, B en C word gedefinieer op ‘n steekproefruimte S. Die gebeurtenisse is onderling uitsluitend en hulle vereniging is S. Verder is gebeurtenis B twee keer meer waarskynlik as gebeurtenis A, en gebeurtenis C is twee keer meer waarskynlik as gebeurtenis B. Die waarskynlikheid van elk van die drie gebeurtenisse is onderskeidelik / Events A, B, and C are defined on a sample space S. The events are mutually exclusive and their union is S. Furthermore, event B is twice as likely to occur as event A, and event C is twice as likely to occur as event B. The probability of each of the three events are, respectively

Veronderstel die volgende gebeurtenisse: / Suppose the following events:

A = student slaag Statistiek en Datawetenskap 188 / student passes Statistics and Data Science 188

B = student neem Finansiële Rekeningkunde as hoofvak / student takes Financial Accounting as major

Verder / Also

P(A) = 0.38                  P(A | B) = 0.50                        P(A en / and B) = 0.24

Die waarskynlikheid dat ‘n student nie Statistiek en Datawetenskap 188 slaag nie, gegee dat die student Finansiële Rekeningkunde as hoofvak neem. / The probability that student does not pass Statistics and Data Science 188, given that the student does take Financial Accounting as a major.

‘n Onderdele winkel verkoop nuwe en gebruikte onderdele. Sestig persent van die onderdele is gebruikte onderdele. Vyf-en-sestig persent is gebruik of defektief. Indien vyf persent van die winkel se onderdele defektief is, watter persentasie is beide gebruik en defektief. / A part store sells both new and used parts. Sixty percent of the parts in stock are used. Sixty five percent are used or defective. If five percent of the store’s parts are defective, what percentage is both used and defective?

‘n Firma klassifiseer klante op twee maniere, volgens: / A firm classifies its customers in two ways according to:

(I) of die rekening agterstallig is en / whether the account is overdue and

(II) of die rekening nuut is (minder as twaalf maande) of oud. / whether the account is new (less than twelve months) or old.

‘n Analise van die firma se records verskaf ons van die volgende tabel van gesamentlike waarskynlikhede: / An analysis of the firm’s records provides the following table of joint probabilities:

Een rekening word ewekansig geselekteer. / One account is randomly selected.

Indien die rekening nie agterstallig is nie, wat is die waarskynlikheid dat dit ‘n nuwe rekening is? / If the account is not overdue, what is the probability that it is new?

Veronderstel daar is 100 studente in u klas, waarvan tien linkshandig is. Twee studente word ewekansig gekies (sonder terugplasing). / Suppose there are 100 students in your class, of whom ten are left-handed. Two students are selected at random (without replacement).

Wat is die waarskynlikheid dat beide linkshandig is: / What is the probability that both are left-handed:

Die maandelikse verhuringskoste per vierkante meter vir kantoorruimte in 25 geboue in Durban se middestad (in rand) word in die volgende frekwensieverdeling gegee: / The monthly rental cost per square meter for office space in 25 buildings in Durban’s centre (in Rand) is given in the following frequency distribution: 

Die verdeling van die data is / The distribution of the data is 

Die volgende totale word gegee vir ’n steekproef wat uit 105 waardes bestaan: / The following totals are given for a sample consisting of 105 values:

Bereken die gemiddeld. / Calculate the mean.

ʼn Sportwinkel eienaar het sy daaglikse omset vir 300 handelsdae aangeteken soos in die frekwensietabel hieronder gegee. / A sport shop owner recorded the daily turnover of his outlet for 300 trading days as shown in the frequency table below.

Wat is die minimum waarde wat die omset moet wees vir ʼn handelsdag om geklassifiseer te word as een van die 25% besigste dae? / What is the minimum turnover which will classify a trading day as one of the 25% busiest?