In a bag containing 3 black balls and 2 red balls , a ball is picked at random then replaced. A second ball is chosen. What is the probability of :

I. both balls being black II. one is black ,the other is red.

2.in a class of 22 boys and 18 girls , two students are to be selected .
What is the probability of selecting two students of the same sex.​

Cd is the perpendicular bisector of both xy and st, and cy=20. find xy.

Paula makes stained-glass windows and sells them to boutique stores. if her costs total $12,000 per year plus $4 per window for the frame. how many windows must she produce to earn a profit of at least $48,000 in one year if she sells the windows for $28 each? 1. define a variable for the situation. 2. write an inequality that represents her profit. note: revenue is money coming in. cost is money going out. profit is the difference between the revenue and the cost. in other words: revenue - costs profit 3.using words, describe how many windows she must sell to have a profit of at least $48,000.

Grandpa ernie is shrinking! over the past 4 years his height decreased by a total of 2.4 cm. it decreased by the same amount each year. what was the change in grandpa ernie's height each year