The answer for the first question in is independent 1/4, because both events of flipping the coin have the same chance to be either heads or tails.
The way to find the probabiltiy is: HH HT TH TT
You determine all possible outcomes
The answer for the second question is independent 49/144
As long as there is replacement, the events are independent.
The probability of both/all events occurring is found by multiplying the probabilities of the individual events. 7/12 * 7/12 = 49/144
Hope this helps ;-)