Posted by Sue on Saturday, August 14, 2010 at 6:57am.
Please help!!!
The mass of a particular substance is known to grow exponentially at a rate of 1.5% per day. Its initial mass was 230 grams and, after t days, it weighed 325 grams.
The equation modelling this growth is
230×1.015 t = 325.
Use the method of taking logs to solve this equation for t, giving your answer correct to the nearest day.

Maths  Reiny, Saturday, August 14, 2010 at 8:50am
I think you have a typo, and meant to say ...
230(1.015)^t = 325
(your equation would have a linear growth, not exponentially)
1.015^t = 325/230 = 1.4130435
log(1.015^t) = log 1.4130435
t = log 1.4130435/log 1.015 = 23.222
so it will take appr. 23 days.
Answer This Question
Related Questions
 maths  The mass of a particular substance is known to grow exponentially at a ...
 Chemistry  Assume that a reaction occurs in which unknown substances R and S ...
 math  Kittens weigh about 100 grams when born and gain 7 to 15 grams per day. ...
 Calculus Help Please!!!  A radioactive substance has a halflife of 4 days. ...
 Chemistry Help Please!!!  A radioactive substance has a halflife of 4 days. ...
 calculus  The rate at which an amount of a radioactive substance decays is ...
 MATH!  The mass of a radioactive substance follows an exponential decay model, ...
 Algebra  Can you PLEASE check  I"m stuck!  Bob is studying the growth of a ...
 Exponential Modeling  The halflife of a radioactive substance is one day, ...
 calculus  assume the halflife of the substance is 31 days and the initial ...
More Related Questions