If you are dealt 4 cards from a shuffled deck of 52 cards, find the probability that all 4 cards are picture cards

The volume of gas a balloon can hold varies directly as the cube of its radius. imagine a balloon with a radius of 3 inches can hold 81 cubic inches of gas. how many cubic inches of gas must be released to reduce the radius down to 2 inches?

X/y + 4y/x divided by x/y - 2y/x explain as in depth as you can how you simplfied the fractions. i don't know where to start on this : /

Find the area of the region that is inside r=3cos(theta) and outside r=2-cos(theta). sketch the curves.