Question

A coin is tossed three times.What is the probability of getting (1)at least 2 heads and (2)atmost 2 tails

Answer 1

Head=H
Tail=T

IF we toss 1 coin . Probability of Result
=(H,T)
Total 2 outcomes

If we toss 2 coins Probability of result
=(H,T)(H,H)(T,T)(T,H)
Total 4 Outcomes

IF we toss 3 coins.probability of result
=(HHH), (HHT),( HTH), (HTT), (THH), (THT),( TTH )( TTT.)
Total 8 outcomes

Probability=favourable result/Total outcomes

(1)Getting at least 2 heads
2 Heads are on 4 coins.
(HHH)(HHT)(HTH)(THH)
Probability=4/8
Probability=1/2

(2)Getting atmost 2 tails
2 Tails are on 4 coins
(HTT)(THT)(TTH)(TTT)
Probability=4/8
Probability=1/2