If you shout on the moon, will the sound travel faster or slower than on earth? why?

As long as the sound is inside the helmet of your space suit, it will travel

at the same speed as it would on Earth, through the same mixture of gases

at the same pressure. Once it passes through the visor of your space helmet,

its 'speed' has no meaning, since there's nothing for sound to travel through on

the moon, and it doesn't travel at all.