Refer to the exhibit.
Host A pings interface S0/0 on router 3. What is the TTL value for that ping?
The default TTL is 255, and as a packet passes through a router the TTL is decremented. By the time the ping packet reaches S0/0 on Router 3, it has passed through two routers and the TTL is now 253. Note that the S0/0 interface responds to the ping: the packet is not routed by Router 3 and so the TTL in the ping packet is not decremented to 252.