4.2% means 0.042 .
4.2% more than some amount is 1.042 of it.
Interest compounded annually means that a year after you deposit some money
into your bank account, the bank looks to see how much of your money has been
there for a year, and they add 4.2% of that into your account. Another way to
look at it is that they change the balance in your account, from the amount it was
a year ago, to 1.042 of that amount. That's right. They just <u>give</u> you free money !
Why that's so good is: Now the new amount in your account is 1.042 of
the amount you originally deposited, and after another year, they'll give you
another 4.2% of <em><u>that</u></em> larger amount. Then you'll have (1.042)² = about <em><u>
8.6% more</u></em><em /> than your original deposit, 2 years earlier.
At the end of any number of years ... call it 't' years ... the amount in your
account is the amount you deposited, multiplied by (1.042)^'t' power.
If you just put some money into this particular bank, and forget about it
and never touch it, you'll have <em><u>double</u></em> the amount in 17 years.
Now we can go and take care of Rhonda.
She put $3000 into a new account at the the bank, and then she forgot
about it and never touched it. How much is in that account after 't' years ?
The amount that's in that account at any time is called the 'balance'.
How much is it after 't' years ?
<em> Balance = 3,000 (1.042)^'t' power .</em>
30 is the answer because 30*25=750
The answer to your question is A. rational numbers.
Rational numbers are closed under any set of operations.
Integers are not closed under division because 1/2 is not an integer.
The set {-1, 0, 1} is also not closed under division because -1/5 does not fall in that set.
Whole numbers are not closed under division because 5/3 will produce a number that is not a whole integer.
Your answer is A. rational numbers.
-4 and 7 would be the answer
