Which expression represents the number of possible combinations of n items taken r at a time?

Dos motos, A y B, toman la salida en una carrera de 90 km. La moto A realiza el recorrido con una velocidad media inferior en 20 km/h a la de la moto B, con lo que llega a la meta 3 minutos después que B. Calcula la velocidad de cada moto.

100 10, UUS 11. A ball is thrown upward at a velocity of 15 meters per second from a height that is 20 meters above the ground. The height h (in meters) of the ball at time t in seconds) after it is thrown can be found by h (t) = - 5t^2 + 15t + 20.

beth sold half of her comic books and then bought nine more. shoe now has 28. with how much did she begin?

A rectangular quilt is to contain 1900 square centimeters. one side is to be 40 centimeters longer than the other. which statement will allow you to find the length of the quilt?

48 is what percent of 52?

Simplify 1) 3b + b + 6 = 2) n + 5n - 3c = 3) 12d - 2d + e =

If h = 21 units and r = 7 units, what is the volume of the cone shown above? Use 3.14 for.

Convert the fraction 2/5 to a decimal and a percent. Show all of your work and explain your answer.

There are 4 consecutive integers that add up to 354. What is the least of the 4 integers?

Tanya runs a catering business. Based on her records, her weekly profit can be approximated by the function LaTeX: f/left (x/right) = 2x^2-44x-150f (x) = 2 x 2 - 44 x - 150, where LaTeX: xxis the number of meals she caters.