The urethra is SHORTER in females than in males.
Explanation:
The male urethra in 15-20cm long, apart from urine addition it also transfers semen(i.e. contains spermatozoa and secreation from sex gland). But when it comes to female it is shorter than males, size is just 4cm, it starts at the neck of bladder.
As it directly opens onto the perineum, females are more susceptible to urinary tract infection than males. This usually known as cystitis i.e. infection in bladder. Simple infections can be cured with 3days antibiotic course.