If a right rectangular pyramid is sliced perpendicular to its base into two congruent pieces, which two-dimensional plane section could result from the slice? A circle
B pentagon
C rectangle
D triangle

Me! 50 points! why does when we come home, our door is unlocked and there is grease on the door knob, me solve this , and i don't know what category this goes under

Combine like terms to make a simpler expression 3z+z

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.