The answer is 2 people. Jim and Holly are 2 persons making 2 gingerbreads for 2 minutes. So, for both of them, 2 minutes are necessary for 2 gingerbreads. Let's calculate how many gingerbreads they can make for 400 minutes. 2 min : 2 gingerbreads = 400 min : x gingerbreads. x = 2 gingerbreads * 400 min : 2 min = 400 gingerbreads. So, the two of them can make 400 gingerbreads for 400 minute without anyone's help.
