promises question added

Author: suman-saket

code-snippets/promises.md

@@ -24,4 +24,51 @@
 </details>
 
 </li>
+
+---
+
+<li>
+
+**Which of the following isn’t a method of Javascript Promise?**
+
+- A: `Promise.then()`
+- B: `Promise.all()`
+- C: `Promise.error()`
+- D: `Promise.catch()`
+
+<br/>
+<details>
+<summary><b>Answer</b></summary>
+<p>
+
+#### Option: C
+
+</p>
+</details>
+</li>
+
+---
+
+<li>
+
+**Which of the following isn’t a state of Javascript Promise?**
+
+- A: `fulfilled`
+- B: `awaited`
+- C: `pending`
+- D: `rejected`
+
+<br/>
+<details>
+<summary><b>Answer</b></summary>
+<p>
+
+#### Option: B
+
+</p>
+</details>
+</li>
+
+---
+
 </ol>