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 (say on Rs.1) and head up on the second coin (Rs.2).Similarly (H, T) means head up on the first coin and tail up on the second coin and so on.
The outcomes favorable to the event E,at least one head' are (H, H), (H, T) and (T, H).
So. the number of outcomes favorable to.E is 3.
Therefore, P(E)=3/4
i.e., the probability that Harpreet gets at least one head is 3/4.