Can you tell me how to solve this.

the largest side of a triangle is six more units than the smallest side. the third side is twice the smallest
side. if the perimeter of the triangle
is 25 units, write and solve an equation to find the lengths of all three sides
of the triangle.

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?