Ascientific calculator has 40 buttons, of which are white, 1/5 are grey, and 4 are orange. the rest of buttons are black. how many black buttons does the calculator have?

The magnitude, m, of an earthquake is defined to be m=log l/s, where i is the intensity of the earthquake (measured by the amplitude of the seismograph wave) and s is the intensity of a “standard” earthquake, which is barely detectable. what is the magnitude of an earthquake that is 1,000 times more intense than a standard earthquake? use a calculator. round your answer to the nearest tenth.

The cost of using a service is $0.25 per min. what equation correctly represents the total cost c, in dollars, for d days of use?

What is the surface area of a cube with the volume of 729 ft?