We're sorry you are having trouble with the sound on your iPad. Please ensure that your headphones have been unplugged from the device. Try the following:
Look at the Side Switch. If you see a red dot, move the toggle to hide the dot. The mute has been turned off. For more information contact Apple.
If steps 1 and 2 don't solve the problem, try completely shutting down your iPad by pressing and holding the Sleep/Wake button for a few seconds until the red "slide to power off" slider appears, and then slide the slider.