How many 3-digit numbers can be formed using the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, if repetition of digits is allowed?

When a 757 passenger jet begins its descent to the ronald reagan national airport in washington, d. c., it is 3900 feet from the ground. its angle of descent is 6 degrees. how far must the plane fly to reach the run way? a. 37,106 ft b. 37,310.4 ft c. 23,456.6 ft d 2,492.7 ft