Eleven times the quotient of a number and 3 minus 15
To translate the given expression into an equation, let's start by assigning a variable to the unknown number. Let's use "x" for the number.
The quotient of a number and 3 can be written as x/3.
Eleven times the quotient of a number and 3 can be written as 11 * (x/3).
Now subtract 15 from the expression: 11 * (x/3) - 15.
So, the expression "Eleven times the quotient of a number and 3 minus 15" can be written as 11 * (x/3) - 15.