Probability

A number is chosen at random from set S = {x : x is an integer from 1 to 30}. Calculate the probability of getting a factor of 20 or a factor of 8.

• 6/30

• 4/30

• 3/30

• 7/30

Two prefects are chosen at random from five prefects, where three of them are in Form Four and two are in Form Five. Then, calculate the probability that both prefects chosen are in the same form.

• 2/5

• 6/20

• 1/10

• 6/30

A and B are two _______ events if the occurrence of event A does not affect the occurrence of event B and vice versa.

• independent

• dependent

A and B are _______ events meaning there is no intersection between events A and B.

• mutually exclusive

• non-mutually exclusive

The probability of Kam Seng passing his Physics and Chemistry tests are 0.58 and 0.42 respectively. Calculate the probability that Kam Seng passes only one test.

• 0.2436

• 0.5128

• 0.1764

• 0.3362

A box contains three yellow pens, five red pens and a black pen. Two pens are chosen at random from the box. Calculate the probability that both pens chosen are of the same colour.

• 6/72

• 20/72

• 1/9

• 13/36

Seven cards labelled with the letters “G, E, M, B, I, R, A” are put in a box. A card is chosen at random from the box. Calculate the probability that the card chosen is labelled with a vowel or letter “R”..

• 4/7

• 3/7

• 1/7

• 2/7

Box T contains five cards labelled with the letters “C, E, L, I, K”. Two cards are taken out randomly one by one from box T without replacement. Calculate the probability of getting the first card labelled with a consonant and the second card labelled with a vowel.

• 3/10

• 2/5

• 3/5

• 1

"Answer three objective questions with four options correctly if the answer of each question is chosen at random." The event is...

• dependent

• independent

"A fair dice is rolled and a fair coin is tossed simultaneously." What is the total number of possible outcomes for the combined events?

• 12

• 6

• 2

• 3