Round 345 to one significant 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

Multiplying fractions by whole number 5 x 1/3=?

Find the common ratio of the sequence. -4, 8, -16, 32, a: -12b: -2c: 12d: -1/-2