Introduction:
Coin toss is one of the simplest forms of probability experiments. It can be used to explain various concepts of probability. In this question, we need to find the probability of getting exactly one head when a coin is tossed simultaneously.

Understanding the problem:
When a coin is tossed simultaneously, there are two possible outcomes - heads or tails. The probability of getting a head is 1/2, and the probability of getting a tail is also 1/2. We need to find the probability of getting exactly one head, which means one coin should show heads and the other should show tails.

Solution:
There are two coins, and each coin can show two possible outcomes. Therefore, the total number of possible outcomes is 2 x 2 = 4. The four possible outcomes are:

1. Head - Head
2. Head - Tail
3. Tail - Head
4. Tail - Tail

Out of these four outcomes, only one outcome satisfies the condition of exactly one head, which is the second outcome - Head-Tail. Therefore, the probability of getting exactly one head is 1/4.

Conclusion:
The probability of getting exactly one head when a coin is tossed simultaneously is 1/4. This can be explained by understanding the possible outcomes and the condition of exactly one head.