D2 -10d + 25
Cuanto da ahí

1/8

Step-by-step explanation:

one way we can solve this is by making a tree  using H for heads and T for tails

since it can land H or T, we put them down like this. then we can get H or T again because its a coin, so we put that under each letter. finally we do the same thing again to get 8 possibilities. now we can count how many of them was HHH, which is one

         H              T

         /  \            /   \

       H   T         H   T

      /\     /\        /\    /\

    H T H T     H T H T

    ^      this one

or do 2 x 2 x 2 because there are 2 possibilities each three times