A bag contains 120 marbles. Some red and the rest are black . There are 19 red marbles for every black marble how many red marbles are In the bag explain your reasoning Can someone please explain this in a 6th grade way

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?

Write as a product: ac^2–ad+c^3–cd–bc^2+bd

Use the distance formula to find the distance between (-3,5) and (3,1)