Ihave trouble understanding word problems. may i have with number 15? you very much!

What is the best reason for jacinta to have a savings account in addition to a checking account

The hawaiian alphabet has 12 letters. how many permutations are posible for each number of letters?

He weights of 2-pound bags of best dog food are approximately normally distributed with a given mean  and standard deviation  according to the empirical rule, what percentage of the bags will have weights within 3 standard deviations of the mean? 47.5%68%95%99.7%