DHT11 not giving correct value if I attaching a servo motor
Your code looks like there is no bug in there.  You might want to look at using a library that lets you assign a pin in the constructor, so you don't need to read from a specific pin.  There might be something internal going on that you don't know (or want to know) about.  As for the movement of the servos do you realise you a rotating 181 degrees int p = 0; p &lt;= 180 is 181 degrees, drop the = if you wanted 180.  Also pos++ is the same as pos += 1 but requires less of those tiring key presses :)

You say that the DHT11s work on their own.  The servo works on its own.  So it not a hardware fault.  I assume its not a wiring fault, but please double check.  That means it has to be something to do with the power.  If you are powering the servo from a digital pin then this is unlikely to work, try powering it from the 5V output pin on the other side of the board.

However if you are powering it from the 5V output pin and it doesn't work then you need to power it from a external source, a mobile phone charger will do (if you have one you can chop the plug off).  The problem with using external PSU is you must tie the grounds together.  Doing this means the Arduino and the external device agree what zero volts is and things work.  This is easily done by taking the gnd of the PSU and putting it in the GND connector of the Arduino and the taking the GND for the servo from the other GND on the Arduino.

I hope that all makes sense, if not tell me what you need clarifying.