65% of what number is 78?

Quick

This is the number of parts out of 100, the numerator of a fraction where the denominator is 100. submit

(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

What numbers are included in the set of integers? what numbers are not included?