How many three-digit numbers can be formed under each condition? (a) The leading digit cannot be zero.

(b) The leading digit cannot be zero and no repetition of digits is allowed.

(c) The leading digit cannot be zero and the number must be a multiple of 3.

(d) The number is at least 400.

Antonio made a scale model of a building. the model's scale is 1 inch to 235 feet and its height is 3.5 inches. what is the exact height of the actual building? enter your answer in the box.

Do more republicans (group a) than democrats (group b) favor a bill to make it easier for someone to own a firearm? two hundred republicans and two hundred democrats were asked if they favored a bill that made it easier for someone to own a firearm. how would we write the alternative hypothesis?

Azul has 4 green picks and no orange picks. you add orange picks so that there are 2 orange picks for every 1 green pick. how many picks are there now.