What is a variable? Why is it helpful in programming?

Given int variables k and total that have already been declared, use a while loop to compute the sum of the squares of the first 50 counting numbers, and store this value in total. thus your code should put 11 + 22 + 33 + + 4949 + 50*50 into total. use no variables other than k and total.

Suppose a router has built up the routing table shown in the table. subnet number 128.96.39.00 28.96.39.128 128.96.40.00 192.4.153.0 default) subnet mask 255.255.255.128 255.255.255.128 255.255.255.128 255.255.255.192 nexthop interface 0 interface 1 r2 r3 r4. the router can deliver packets directly over interfaces 0 and 1, or it can forward packets to routers r2, r3, or r4. describe what the router does with a packet addressed to each of the following destinations: (a) 128.96.39.10 (b) 128.96.40.12 (c) 128.96.40.151 (d) 192.4.153.17 (e) 192.4.153.90

Between 1932 and 1938, chester carlson developed a process that enabled a "picture" of a document to be taken and then have it reproduced on another