Fixed typo in .find exercise

Author: sourabhbagrecha

docs/40-CRUD/1-WHERE.mdx

@@ -109,7 +109,7 @@ Now, translate the following into a MongoDB query.
   </div>
 </details>
 
-#### 3. Find books in the "Science" genre that have more than 300 pages.
+#### 3. Find books in the 'Science' genre that are more than 300 pages long.
 
 <details>
   <summary>Answer</summary>