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According to an ancient belief, when a friend visits a sick person, \(\frac{1}{60}\) of his or her illness is taken away. How many friends need to visit to take away at least 99% of a person's illness?

A. 375

B. 180

C. 275

D. 125

E. 55

Please explain, I am confused on this problem

CalculatorUser Feb 16, 2019

#1**+3 **

If 1/60 is taken away after a visit .....then 59/60 must remain after a visit

So.....we want to find out how many visits are required to have 1% = 1/100 left

So.....we want to solve this

(59/60)^N = 1/100 where N is the number of required friends

Take the log of both sides

log (59/60)^N = log (1/100) and by a log property, we can write

N * log (59/60) = log (1/100) divide both sides by log(59/60)

N = log(1/100) / log (59/60) ≈ 274.001 friends

We'll call 275 good .....!!!

CPhill Feb 16, 2019