In a certain code language ‘617’ means ‘sweet and hot’, ‘735’ means ‘coffee is sweet’ and ‘263’ means ‘tea is hot’. Which of the following would mean ‘coffee is hot’?

Let us find the unique digits for each word by comparison:
1. Compare ‘617’ ("sweet and hot") and ‘735’ ("coffee is sweet"): The common word is "sweet" and the common digit is $7$. So, $\text{sweet}=7$.
2. Compare ‘617’ ("sweet and hot") and ‘263’ ("tea is hot"): The common word is "hot" and the common digit is $6$. So, $\text{hot}=6$.
3. From ‘735’ ("coffee is sweet"), since $\text{sweet}=7$, the remaining digits $3$ and $5$ correspond to "coffee" and "is".
4. From ‘263’ ("tea is hot"), since $\text{hot}=6$, the remaining digits $2$ and $3$ correspond to "tea" and "is".
5. Comparing steps 3 and 4, the common word is "is" and the common digit is $3$. So, $\text{is}=3$.
6. This leaves $\text{coffee}=5$.

Now compile the code for “coffee is hot”:

* $\text{coffee}=5$
* $\text{is}=3$
* $\text{hot}=6$

The digits are $5,3,6$, which matches the combination $536$.