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Intern
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i have a couple of math questions: 1) if X is 40% of Y, and [#permalink]
 29 Oct 2004, 17:00
i have a couple of math questions:
1) if X is 40% of Y, and Y is 70% of Z, then X is what % of Z?
how do you figure this out? do you just get common denominators and figure the X to Y relationship to find out X's % for Z?
2) for DS, if three acounts have 20,000, 30,000, and 40,000 respectively and they all have the same interest rate and the same number of years, can you find out the value for the 20,000 account at X interest rate and Y years?
the following are given:
a) after X years and Y interest, the new 30,000 value is given (dont remember the exact number)
b) after X years and Y interest, the new 40,000 value is given
thanks for your help.
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GMAT Club Legend
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You can figure out first question in 10 seconds. Just assign a value to Z. To make it easy, let z = 100. y is then = 70. 10% of y is 7. To get 40% of y, multiply 7 by 4 and you get 28%
_________________
Best Regards,
Paul
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Intern
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thanks for the quick reply. any guess on the other question. i'm thinking that the answer might be C since if using both a) and b) you have two equations with two variables (interest and year).
thanks again.
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Director
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Regarding your second question :
If you consider A amount of money in a mutual fund with X % of annual interest rate (compounded) during Y years, result is
A.(1+X)^Y = new amount
What you need to assess the new value of your 20000 initial installment is only (1+X)^Y = A'/A
So I would answer D
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sorry...i guess i'm having trouble understanding...
how can you figure out the X and Y of the 20,000 account when all you have is the end amount for the 30,000 and 40,000 accounts and given that X and Y are the same (but these exact values are not given)?
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close
