Krishna tosses 2 fair coins simultaneously. What is the probability he gets at least one head?
Krishna tosses 2 fair coins simultaneously. What is the probability he gets at least one head?
The correct option is C 0.75
Let 'H' stand for getting head and 'T' for getting tail. When two coins are tossed simultaneously, the possible outcomes are (H, H), (H, T), (T, H), (T, T), which are all equally likely. Here (H, H) means head up on the first coin and head up on the second coin. Similarly (H, T) means head up on the first coin and tail up on the second coin and so on.
The outcomes favourable to the event E, 'at least one head' are (H, H), (H, T) and (T, H). Note that here both the cases of one head and 2 heads are considered. This is because in question it is stated 'at least one head'. This includes the case of 2 heads also.
So, the number of outcomes favourable to E is 3. Total number of possible outcomes is 4.
Therefore P(E) = 34 = 0.75
The probability that Krishna gets at least one head = 0.75
Hence the correct Option is C.
0.75
Let 'H' stand for getting head and 'T' for getting tail. When two coins are tossed simultaneously, the possible outcomes are (H, H), (H, T), (T, H), (T, T), which are all equally likely. Here (H, H) means head up on the first coin and head up on the second coin. Similarly (H, T) means head up on the first coin and tail up on the second coin and so on.
The outcomes favourable to the event E, 'at least one head' are (H, H), (H, T) and (T, H). Note that here both the cases of one head and 2 heads are considered. This is because in question it is stated 'at least one head'. This includes the case of 2 heads also.
So, the number of outcomes favourable to E is 3. Total number of possible outcomes is 4.
Therefore P(E) = 34 = 0.75
The probability that Krishna gets at least one head = 0.75
Hence the correct Option is C.
