@Nitesh

Read the best chosen answer, and plz read all the discussion before make any comment https://gateoverflow.in/1265/gate2007-67-isro2016-72

we discussed a lot , and for that geeksforgeeks link they follow old standards .

In GATE exam number of hosts always 2^{h}-2 and two times this types of question came and in both questions host we calculate using 2^{h}-2

Now number of subnet is 2^{n} in new standard , in GATE last time they ask this question in 2007, that time they follow old standard which is evident from their options.

Now coming to GATE 2007 question, the correct answer is 64, 1022 but as No option matches we have to select 62,1022 which is option C .