#Python, 42 bytes#

import random
lambda n:1>random.random()*n

Edit: Removed the time.time() answer because of the distribution.

Python, 42 bytes

import random
lambda n:1>random.random()*n

Edit: Removed the time.time() answer because of the distribution.

#Python, 36 bytes#

import random
lambda n:1>random.random()*n

Edit: Using the current time instead of random.random(), seven bytes are saved:

import time
lambda n:1>time.time()%n

#Python, 42 bytes#

import random
lambda n:1>random.random()*n

Edit: Removed the time.time() answer because of the distribution.

#Python, 36 bytes#

import random
lambda n:1>random.random()*n

50 bytes if function is named:

import random
def f(n):return 1>random.random()*n

Edit: Using the current time instead of random.random(), seven bytes are saved:

import time
lambda n:1>time.time()%n

#Python, 36 bytes#

import random
lambda n:1>random.random()*n

Edit: Using the current time instead of random.random(), seven bytes are saved:

import time
lambda n:1>time.time()%n