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.
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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 .
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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% .
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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% .
