$\"\"$

The word $\"\"$ twice $\"\"$ represents multiplication operation and the symbol is $\"\"$ .

The word $\"\"$ quotient $\"\"$ represents division operation and the symbol is $\"\"$ .

The word $\"\"$ sum $\"\"$ represents addition operation and the symbol is $\"\"$ .

The word $\"\"$ The sum of a number y and 8 $\"\"$ represents $\"\"$ .

The word $\"\"$ The quotient of 50 and the sum of a number y and 8 $\"\"$ represents $\"\"$ .

The word $\"\"$ Twice the quotient of 50 and the sum of a number y and 8 $\"\"$ represents $\"\"$ . $\"\"$

The option C is correct answer.