1). $2,700 is (2,700/6,000) = 45% of 6,000. It took 6 years to earn it, so it earned (45%/6) = 7.5% each year. That's the simple-interest rate. _________________________________ 2). The investment earns 4.5% each year, so it earned 9% in 2 years. The $1,150.65 is the 9% of the original investment. Call it V. 1150.65 = 0.09 x V . Divide each side by 0.09 : V = 1150.65 / 0.09 = $12,785 . ____________________________________ 3). There are 18 marbles in the bag all together. a). 8 of them are green. If you close your eyes and pull out 1 marble, the probability that it's a green one is 8/18 = 4/9 = 44.4% . b). If it was a red marble, and you put it in your pocket, then there are only 17 in the bag now, and 8 of them are still green. If you pull another one, the probability that it's green is 8/17 = 47.1% . ____________________________________ 5). There are 10 marbles in the bag all together. (The second sentence doesn't say anything, and doesn't mean anything.) If you pull out a silver marble and put it in your pocket, then there are 9 marbles in the bag, and 2 of them are orange. The probability of pulling an orange marble now is 2/9 = 22.2% .