4. Three coins are tossed once. Let A denote the event ‘three heads show”, B denote the event “two heads and one tail show”, C denote the event” three tails show and D denote the event ‘a head shows on the first coin”. Which events are
(iii) Compound?
Sample space when three coins are tossed = [Sample space when a coin is tossed thrice!]
S = {HHH, HHT, HTH, THH, TTH, TTT}
Now,
A = Event that three heads show up = {HHH}
B = Event that two heads and one tail show up = {HHT, HTH, THH}
C = Event that three tails show up = {TTT}
D = Event that a head shows on the first coin = {HHH, HHT, HTH, HTT}
(iv). If an event has more than one sample point, it is called a Compound event.
B = {HHT, HTH, THH} and D = {HHH, HHT, HTH, HTT}
Hence, B and D are compound events.