Test: Probability - Year 7 MCQ

There are two prime numbers (2, 3) out of six possible outcomes, so the probability is 2/6 = 1/3

The probability of picking a red marble is 

The probability of event A not happening is 1 - 1/4 = 3/4.

The multiples of 3 on the spinner are 3 and 6, so the probability is 2/8 = 1/4.

The probability of the complementary event is 1 - 0.75 = 0.25

There are 26 cards that are hearts or diamonds out of 52, so the probability is 26/52 = 1/2.

The probability of drawing a red ball first is 4/10 and the probability of drawing a red ball second, after one has already been removed, is 3/9. 

Therefore, the combined probability is 4/10 x 3/9 = 2/15.

The probability of event B happening twice in a row is 

The pairs that sum to 7 are (1,6), (2,5), (3,4), and (4,3), (5,2), (6,1). There are 6 such pairs out of 36 possible outcomes, so the probability is 6/36 = 1/6.

The number of students who play at least one sport is 18 + 12 - 6 = 24. The probability is 24/30 = 4/5.