Question

A coin is tossed two times. What are the probability of getting a head and a tail?
1. \(\frac{1}{8}\)
2. \(\frac{1}{4}\)
3. \(\frac{1}{2}\)
4. \(\frac{3}{4}\)

Answer 1

Correct Answer - Option 3 : \(\frac{1}{2}\)

Concept:

Probability of an event happening = \(\frac{{{\rm{Number\;of\;ways\;it\;can\;happen}}}}{{{\rm{Total\;number\;of\;outcomes}}}}\)NumberofwaysitcanhappenTotalnumberofoutcomesNumberofwaysitcanhappenTotalnumberofoutcomes 

Calculation:

A coin is tossed 2 times

Sample Space = {(H,H) , (H,T) , (T,H) , (T,T) }

∴ Total no of Outcomes = 4

Taking head and tail 

Thus, Favourable outcomes are = {(H, T), (T, H)} = 2

∴ Probability of getting head and tail alternately = 2/4 = 1/2