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Math Revolution GMAT Instructor
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Let A=2^50, B=3^30, and C=5^20. Which of the following is true?
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20 Feb 2018, 00:38
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[GMAT math practice question] Let \(A=2^{50,} B=3^{30}\), and \(C=5^{20}\). Which of the following is true? A. A<B<C B. A<C<B C. C<A<B D. B<C<A E. C<B<A
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Re: Let A=2^50, B=3^30, and C=5^20. Which of the following is true?
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20 Feb 2018, 03:48
MathRevolution wrote: [GMAT math practice question]
Let \(A=2^{50,} B=3^{30}\), and \(C=5^{20}\). Which of the following is true? A. A<B<C B. A<C<B C. C<A<B D. B<C<A E. C<B<A HCF of \(50\), \(30\) & \(20\) is \(10\), so arrange the numbers to the power of \(10\) to get a clear picture \(A=2^{50}=(2^5)^{10}=32^{10}\) \(B=3^{30}=(3^3)^{10}=27^{10}\) \(C=5^{20}=(5^2)^{10}=25^{10}\) Clearly, \(A>B>C\) Option E




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Re: Let A=2^50, B=3^30, and C=5^20. Which of the following is true?
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20 Feb 2018, 03:46
MathRevolution wrote: [GMAT math practice question]
Let \(A=2^{50,} B=3^{30}\), and \(C=5^{20}\). Which of the following is true? A. A<B<C B. A<C<B C. C<A<B D. B<C<A E. C<B<A Unconventional methodNo of digits in A= 2^50 = 50 log 2 ( here log 2 is of the base 10 ) = 50 x 0.3010 = 15.xx = 15 + 1 = 16 digits No of digits in B = 3^30 = 30 log 3 = 30 x .4771 = 14.xx = 14 +1 = 15 digits No of digits in C = 5^20 = 20 log 5 = 20 x 0.69 = 13.xx = 14 digits Now greater the digits greater the number ( in positive numbers) thus C<B<A / A > B>C (E) imo PS don't try this on the gmat if you are not sure of Log values I'm sure there are other ways to solve this but this was the only method I could think of



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Let A=2^50, B=3^30, and C=5^20. Which of the following is true?
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20 Feb 2018, 03:50
Hatakekakashi wrote: MathRevolution wrote: hi HatakekakashiTruly unconventional I am sure hardly anyone of us would remember log values at this age



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Re: Let A=2^50, B=3^30, and C=5^20. Which of the following is true?
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20 Feb 2018, 03:51



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Re: Let A=2^50, B=3^30, and C=5^20. Which of the following is true?
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20 Feb 2018, 03:54
niks18 wrote: hi HatakekakashiTruly unconventional I am sure hardly anyone of us would remember log values at this age haha :D well that's true but squares 150 cubes 1  15 0 is not positive log 1 to 5 1 is not prime i do remember these things most of the times



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Let A=2^50, B=3^30, and C=5^20. Which of the following is true?
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Updated on: 20 Feb 2018, 07:55
MathRevolution wrote: [GMAT math practice question]
Let \(A=2^{50,} B=3^{30}\), and \(C=5^{20}\). Which of the following is true? A. A<B<C B. A<C<B C. C<A<B D. B<C<A E. C<B<A We can write as  \(A = (1024)^{5}, B = (729)^{5}, C = (625)^{5} Hence, A>B>C\)
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Re: Let A=2^50, B=3^30, and C=5^20. Which of the following is true?
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20 Feb 2018, 07:50
rahul16singh28 wrote: MathRevolution wrote: [GMAT math practice question]
Let \(A=2^{50,} B=3^{30}\), and \(C=5^{20}\). Which of the following is true? A. A<B<C B. A<C<B C. C<A<B D. B<C<A E. C<B<A We can write as  \(A = (1024)^{50}, B = (729)^{5}, C = (625)^{5} Hence, A>B>C\) 1024^5 you mean? Posted from my mobile devicePosted from my mobile device



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Re: Let A=2^50, B=3^30, and C=5^20. Which of the following is true?
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20 Feb 2018, 08:39
Hatakekakashi wrote: rahul16singh28 wrote: MathRevolution wrote: [GMAT math practice question]
Let \(A=2^{50,} B=3^{30}\), and \(C=5^{20}\). Which of the following is true? A. A<B<C B. A<C<B C. C<A<B D. B<C<A E. C<B<A We can write as  \(A = (1024)^{50}, B = (729)^{5}, C = (625)^{5} Hence, A>B>C\) 1024^5 you mean? Posted from my mobile devicePosted from my mobile device1024^5 you mean? (2^10)^5=1024^5
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Re: Let A=2^50, B=3^30, and C=5^20. Which of the following is true?
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22 Feb 2018, 02:10
=> If we wish to compare these numbers, we need to either make their bases the same or make their exponents the same. In this case, it is easiest to make all exponents the same as follows: \(A=2^{50} = (2^5)^{10} = 32^{10}\) \(B=3^{30} = (3^3)^{10} = 27^{10}\) \(C=5^{20} = (5^2)^{10} = 25^{10}\) Since \(32 > 27 > 25\), we must have \(A > B > C\). Therefore, the answer is E. Answer: E
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Re: Let A=2^50, B=3^30, and C=5^20. Which of the following is true?
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20 Apr 2019, 22:41
MathRevolution wrote: [GMAT math practice question]
Let \(A=2^{50,} B=3^{30}\), and \(C=5^{20}\). Which of the following is true? A. A<B<C B. A<C<B C. C<A<B D. B<C<A E. C<B<A We can write this as (2^5)^10 , (3^3)^10, (5^2)^10 > A= 32^10, B= 27^10, C= 25^10 From this we can see that C<B<A




Re: Let A=2^50, B=3^30, and C=5^20. Which of the following is true?
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20 Apr 2019, 22:41






