Which must be true in order for the relationship to be correct? and and and

Afamily has five members. a mom, a dad, two sisters, & a brother. the family lines up single file. what is the probabillity that the mom is at the front of the line

Factor the polynomial. b^2 + 4b + 4

The measurement of one angle of a right triangle is 42° what is the measurement of the third angle? (there is no picture)