You flip three coins. what is the probability of getting at least two heads? How do you know?

Assume that the weights of quarters are normally distributed with a mean of 5.67 g and a standard deviation 0.070 g. a vending machine will only accept coins weighing between 5.48 g and 5.82 g. what percentage of legal quarters will be rejected? round your answer to two decimal places.

Twelve less than a number is at most 20

Find two numbers if their sum is 91 and the ratio is 6: 7?