Final answer:
The fraction '3/12' should be pronounced as 'three twelfths,' and the variable expression 'n/20' should be pronounced as 'n twentieths.' None of the provided options are correct.
Step-by-step explanation:
To pronounce the fraction '3/12' aloud, you would say 'three twelfths,' and for the variable expression 'n/20,' you would say 'n twentieths.' The correct pronunciation for '3/12, n/20' is therefore 'three twelfths, n twentieths.' This means that none of the options provided (three out of twelve, net twenty; three over twelve, not twenty; three for twelve, next twenty; three minus twelve, near twenty) are entirely accurate. The term 'net twenty' does not apply in this context. When reading fractions, it's important to use the correct terminology to distinguish the numerator (top number) and the denominator (bottom number).