How algebra tiles represent like terms and zero pairs

(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

Betty correctly answers 30 questions on your math test there are 40 questions on the test what percent of the questions did she answered incorrectly

An archaeologist in turkey discovers a spear head that contains 53% of its original amount of c-14. find the age of the spear head to the nearest year. (5250 isn’t right)