Some help me with this question please

(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

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

Divide. –40 ÷ –5 a –8 b 200 c -200 d 8