Probability of being rescued in the desert with just 3 calls available

Probability of being rescued in the desert with just 3 calls available

A group of boys has been lost several days in the dessert. This group has
a phone to make phone calls. After a long way walk, they believe that the
current area is suitable for phone calls; even though, the battery just
allow three call attempts. Due to remote conditions of the current area,
the probability of a successful call is 0.2. If the call is not
successful, the network would save a register of their location with a
probability of 0.375. With a probability of 0.625 the attempt was in vain.
If the call attempt was successful or there are 2 registers, they would be
rescued within a few hours the same day.
1.) What is the probability that they are not rescued the same day if that
just depends on the result of the call attempts. 2.) Which is the
probability that the group is rescued with EXACTLY two call attempts 3.)
What is the probability of a successful call 4.) What is the probability
that the network generates register but they are not rescued
I have try a solution by a tree, but i'm blocked with the fact that with 2
calls they are rescued. I really appreciate an explanation, since my
self-learning resources are not extremely complete for wide understanding.
If you think in a tree, how could it be.
I would really appreciate if you can suggest me better resources (books),
to understand this material. Thanks.