Answer:
6/16 or 0.375 ..
Explanation:
Each time the coin has two possible outcomes so tossing the coin four times
The sample space will be: 2^4 = 16
The sample space is: {HHHH, HTHH, THHH, HTHT , HHHT, HTTH, TTHH, THTH, HHTT, HHTH, TTTH, THHT ,HTTT, TTTT, TTHT, THTT}
Let A be the event that there are exactly two heads
A = {HTHT, HTTH, TTHH, THTH, HHTT, THHT}
n(A) = 6
So the probability of exactly two heads is:
P(A) = 6/16 or 0.375 ..