CAIE S1 2024 March — Question 2

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2024
SessionMarch
TopicBinomial Distribution
TypeMultiple independent binomial calculations

2 Sam is a member of a soccer club. She is practising scoring goals. The probability that Sam will score a goal on any attempt is 0.7 , independently of all other attempts.
  1. Sam makes 10 attempts at scoring goals. Find the probability that Sam will score goals on fewer than 8 of these attempts.
  2. Find the probability that Sam's first successful attempt will be before her 5th attempt.
  3. Wei is a member of the same soccer club. He is also practising scoring goals. The probability that Wei will score a goal on any attempt is 0.6 , independently of all other attempts. Wei is going to keep making attempts until he scores 3 goals.
    Find the probability that he scores his third goal on his 7th attempt.