What is log3(4) log4(5)...log80(81)?  Pick one:  A) 1  B) 4  C) 81  D) log80 243  E) e81
Recall the change of base formula   logb(a) =   ln(a)   ln(b)   :   (Alternatively, we can substitute logc for ln on the right, as long as the base is the same on   the top and on the bottom.) Using this, we can rewrite the entire expression using natural   logarithms, as   ln(4)   ln(3)   ln(5)   ln(4)   ln(81)   ln(80)   =   ln(81)   ln(3)   = log3(81) = log3(34) = 4:   correct answer 4
<result>B</result>
What is log3(4) log4(5)...log80(81)?