Grade 8 Math

Problem #1

Gretchen knows the combination to a bank vault lock is two letters followed by two numbers.

a)   What is the probability that Gretchen guesses the combination on her first attempt?

b)   Suppose she knows the combination starts with the letter M. 

Problem #2

Each time Parker shoots a free throw in basketball, he has an 80% chance of making the shot.
Suppose he is given 3 free throws. Find the probability of each event.

a)   Makes the basket, misses the basket, makes the basket

b)   Makes all 3 shots

c)   Misses all 3 shots