How to find out the iso and aperture from a photo i've already taken on my nikon d3000?

I have a photography class and i need to take a picture and find out what the iso and the aperture is. Is there anyway that i can find out what they are from a photo that's already been taken? My camera is a nikon d3000.

Look at the exif data… That should be viewable in "details" in the properties menu on the photo file.

If the image is still on the camera, there's a display button so when viewing the images it will tell the basic stats such as image quality, iso, aperture, shutter speed and show a histogram.

If image is on your computer, use a program which can read the EXIF data embedded within the image file. Opanda is such a program.
http://www.opanda.com/en/iexif/index.html

If you're using a modern version of Photoshop, the EXIF metadata can be read from Photoshop. Many other image editing programs have the ability to read EXIF metadata.

Put the photo in the computer and use your favorite graphics utility to see the EXIF info. It's usually under Properties.

A simpler way is to open the picture in your favorite internet browser. Right-click on the picture and select Properties.