Update pages/instances/faq.mdx

Co-authored-by: Rowena Jones <[email protected]>

Author: bene2k1

pages/instances/faq.mdx

@@ -52,7 +52,7 @@ You can change the storage type and flexible IP after the Instance creation, whi
 
 ## How are Instances billed?
 
-Instances are billed according to the time they are powered on:
+Instances are billed according to how long they remain powered on:
 
 - **CPU Instances**: Charged per hour while powered on or in standby.
 - **GPU Instances**: Charged per minute while powered on or in standby.