An insurance policy pays for a random loss X subject to a deductible of C, Where 0

An insurance policy pays for a random loss X subject to a deductible of C, where 0 < C < l. The loss amount is modeled as a continuous random variable with density function 0, otherwise. Given a random loss X, the probability that the insurance payment is less than 0.5 is equal to 0.64. Calculate C.