x is a positive number. If 9^x + 9^x+1 + 9^x+2 + 9^x+3 + 9^x+4 + 9^x+5 = y, is y divisible by 5?
1) 5 is a factor of x.
2) x is an integer.
isn't the question stem sufficient??
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Divisble by 5
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Bill@VeritasPrep
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We need to know that x is an integer. If x is a decimal, then we could end up with decimal values for our terms, i.e. 9^2.2=~125.7
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Yes the Question can be written as 66430*(9^x)bryan88 wrote:Dont we get 9^(x) *66430 on expansion.
This is anyway divisible by 5.
Am i missing something?
I would refer to Bill's reply.
We need to know that x is an integer.
I first took B as the answer.Bill@VeritasPrep wrote:We need to know that x is an integer. If x is a decimal, then we could end up with decimal values for our terms, i.e. 9^2.2=~125.7
But after seeing the original answer as D, I realized that if 5 is a factor of x, then x is an integer.
A is also sufficient.
Thanks for the question dipzzz
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ihatemaths
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