Which of the following body areas IS susceptible to tzara'at impurity?
Halacha 1 lists exempt areas including the inside of the ear, armpits, nails, and more. The back of the knee (regular skin of the body) is not listed as exempt and can contract impurity.
Question 2
A gentile converts to Judaism and already has a baheret from before his conversion. What happens?
Halacha 4 states that a blemish existing on a gentile at conversion is pure. However, if the shade changed after conversion, it must be given an initial assessment.
Question 3
Two people are isolated: one with a gris-blemish, one with a sela-blemish. After a week, both have sela-blemishes. It's unknown which one spread. What is the ruling?
Halacha 5 states that although one blemish definitely spread, since we don't know which one, both are pure until the specific blemish that spread is identified.
Question 4
Two people were already declared impure. One's spread healed back to the original size, but it's unknown which one. What is the ruling?
Halacha 6: Once impurity has been established, doubt is resolved stringently. Both remain impure until both their blemishes return to the original gris size — this is the principle 'once subject to impurity, doubt = impure.'
Question 5
A person's signs of impurity disappear just before the priest pronounces 'You are impure' at the end of week two. What is the ruling?
Halacha 7 states: if signs disappear before the priest pronounces the ruling, and this is happening at the end of the second week, the person is released (not declared impure), since the signs were gone when the pronouncement was to be made.