Which answer is the product of and its conjugate

Simplify (a/b - b/a) times (a - a^2/a+b) a - a^2/a=b is a mixed number

(a) (8%) compute the probability of an even integer among the 100 integers 1! , 2! , 3! , until 100! (here n! is n factorial or n*(n-1)*(n-2) *… 1) (b) (16%) compute the probability of an even integer among the 100 integers: 1, 1+2, 1+2+3, 1+2+3+4, …., 1+2+3+… + 99, and 1+2+3+… + 100

You love to play soccer! you make a shot at the net 8 times during a game! of those 8 attempts, you score twice. what percent of the time did you score?