Cystic fibrosis is controlled by recessive alleles (cc). if two parents without cystic fibrosis have a child with cystic fibrosis, what is the probability ratio that their next child will have cystic fibrosis?

What do u mean Cystic fibrosis is controlled by recessive alleles (cc). if two parents without cystic fibrosis have a child with cystic fibrosis, what is the probability ratio that their next child will have cystic fibrosis?