JAMB - Mathematics (2023 - No. 21)
A coin is thrown 3 times. What is the probability that atleast one head is obtained?
\(\frac {7}{8}\)
\(\frac {3}{8}\)
None the above
\(\frac {1}{8}\)
คำอธิบาย
Sample space = {HHH, HHT, HTH, THH, TTH, THT, HTT, TTT}
Total number of possible outcomes = 2 x 2 x 2 = 8
favourable number of outcomes = 7
∴Pr(at least one head) = \(\frac {7}{8}\)