Answer: 17
To get this answer, divide 53 over 3 using a calculator or long division. You'll find that 3 goes into 53 a total of 17 times with 2 left over. In other words, the quotient is 17 and the remainder is 2. The 2 left over cups can't be used to make a full batch, so we ignore this part.
See the attached image for a visual of what the long division looks like.