Date | November 2020 | Marks available | 1 | Reference code | 20N.1.SL.TZ0.T_6 |
Level | Standard Level | Paper | Paper 1 (with calculator from previous syllabus) | Time zone | Time zone 0 |
Command term | Find | Question number | T_6 | Adapted from | N/A |
Question
Srinivasa places the nine labelled balls shown below into a box.
Srinivasa then chooses two balls at random, one at a time, from the box. The first ball is not replaced before he chooses the second.
Find the probability that the first ball chosen is labelled .
Find the probability that the first ball chosen is labelled or labelled .
Find the probability that the second ball chosen is labelled , given that the first ball chosen was labelled .
Find the probability that both balls chosen are labelled .
Markscheme
(A1) (C1)
[1 mark]
(A1) (C1)
[1 mark]
(A1)(A1) (C2)
Note: Award (A1) for correct numerator, (A1) for correct denominator.
[2 marks]
(M1)
Note: Award (M1) for a correct compound probability calculation seen.
(A1) (C2)
[2 marks]