How many 4 digit passcodes are possible if no digits are repeated

Bruce is getting materials for a chemistry experiment his teacher gives him a container that has 0.25 liter of liquid in it. bruce need to use 0.4 of this liquid for the experiment. how much liquid will bruce use?

The radius of the base of a cylinder is 10 centimeters, and its height is 20 centimeters. a cone is used to fill the cylinder with water. the radius of the cone's base is 5 centimeters, and its height is 10 centimeters.

Aplane is taking off from bangladesh headed to new york city. at the same time, a plane from new york city is headed to bangladesh is also taking off. the plane bound to new york city is traveling at 600 mph, while the plane traveling to bangladesh is traveling at 400 mph. how far from new york city will the two planes meet if the distance between new york city and bangladesh is 8,000 miles?