In 6 hours a boat, traveling with the current, covers 20 more mi than in 10 hours, traveling against the current. what is the speed of the current if the speed of the boat in still water is 15 mph?

Omar is going on a road trip! the car rental company offers him two types of cars. each car has a fixed price, but he also needs to consider the cost of fuel. the first car costs $90 to rent, and because of its fuel consumption rate, there's an additional cost of s0.50 per kilometer driven.

Credit card a offers an introductory apr of 3.4% for the first three months and standard apr of 15.7% thereafter,

Having a hard time understanding this question (see attachment).