Okay.. say 100 straddle = 10 and the 95-105 strangle = 6... if you sell the IC, you receive 4.
This is your max gain with expiry at 100
Max loss is on or outside the strangle limits. So, expiry at 95 means the 100 put is 5, the rest of the legs = 0.
Expiry at 105 means the 100 call = 5 and the rest =.
Expiry <95 or >105 means that the max value stays 5... At 94: 100 put = 6 and 94 put = 1, value 5.. etc.
So total loss at max = 5-4(credit)=1