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which number is bigger: 5^200 or 2^500?
 Aug 22, 2013
 #1
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in order to solve this problem you have to make your bases the same (similar to what you do with fractions).

instead of having 2^500 & 5^200, why not have 5^z & 5^200, or better yet, 2^500 & 2^w.

But the question is how do you do that? The answer is simple. Express the value of 5 as an exponential expression with a base of two. In other words:

5=2^x, where x is the exponent we need to solve for. Take the logarithm base 2 of BOTH SIDES OF THE EQUATION, and you get this:

log2(5)= x, which means x=2.32...(this number is an approximation)

So now you have 2^2.32= 5, which you can use in the problem above.

5^200= (2^2.32)^200= 2^(2.32*200)= 2^464

And now you can see which one is greater
 Aug 22, 2013
 #2
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Just calculate the number of decimal digits with: Int(log_10(b)*n)+1


[input]log(5)*200+1[/input]
[input]log(2)*500+1[/input]
 Aug 22, 2013

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