i) P(does not like to play computer games AND fails the exam) =
P(fail)-P(fail and likes computer games)P(likes computer games) = 0.22 - 0.6*0.14 = 0.136
iv) P(either likes to play computer games or fails or both) =
P(likes computer games) + P(fails) - P(likes computer games and fails) = 0.14+0.22-0.6*0.14 = 0.276
Draw the Venn diagram for each case and highlight the area of interest for each case above and it will really help you see where these formulas are coming from.