1998 AHSME Problem 22

Algebra Level 2

What is the value of the expression

1 log 2 100 ! + 1 log 3 100 ! + 1 log 4 100 ! + + 1 log 100 100 ! \frac{1}{\log_{2}100!}+\frac{1}{\log_{3}100!}+\frac{1}{\log_{4}100!}+\cdots+\frac{1}{\log_{100}100!}

2 1 .01 10

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Sahil Gohan
Apr 7, 2014

1) Any log with base x and number y can be written as [log(y)/log(x)]

2) if you write the numbers in question in the above manner you will see the numerator as [log2 +log3 + log4+....log100

3) denominator will be common log 100!

4) logA + logB + logC +...logZ = log( A B C .... Z)

5) therefore numerator = log (2 3 4 5..... 100) = log (100!)

6)therefore its log (100!)/ Log(100!) = 1

Although I solved this but i couldn't understand your explaination mind explain in detail?

Zack Yeung - 7 years, 1 month ago

WHY NUMERATOR = log (2345.....100) = log (100!)?? I DONT UNDERSTAND THIS PLEASE EXPLAIN MY FRIEND....THANKIEW

Zack Yeung - 7 years, 1 month ago

oooh i got it thnkiew !! Nice explaination

Zack Yeung - 7 years, 1 month ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...