Alan spent 3 hours building a model for his science project. This was 60% of the total time he spent on the project. How many hours did he work on the project?

Asystem of equations has 1 solution. if 4x-y=5 is one of the equations , which could be the other equation ?

The figure below shows rectangle abcd and the triangle eca on a coordinate plane. which of the following expressions represents the perimeter of triangle of triangle eca in units

The two square pyramids are similar. find the total volume of both pyramids if the ratio of their surface areas is 9/16