Nguyen was climbing a cliff. He stopped for a snack. After that, he climbed 11 feet to the next foothold and then climbed 9 feet to another
foothold. Model the distance Nguyen traveled on the cliff after his
snack as a sum.
HELP PLEASE!!

Iam so stuck. what is the worked out answer for this question?

(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

Which of these triangle pairs can be mapped to each other using two reflections?