document.write( "Question 188851: 1. The current pop. of a small city is 9110 people. If the pop. will increase at an annual rate of 2.78%, how many years will it take for the town to reach a pop of 34253?\r
\n" ); document.write( "\n" ); document.write( "2. The half life of a radioactive substance is ninety(90) day. How many days will it take for seventy-five percent (75%) of the substance to decay?
\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #141659 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
1. The current pop. of a small city is 9110 people. If the pop. will increase at an annual rate of 2.78%, how many years will it take for the town to reach a pop of 34253?
\n" ); document.write( "---
\n" ); document.write( "Equation:
\n" ); document.write( "9110(1.0278)^x = 34253
\n" ); document.write( "1.0278^x = 3.7599
\n" ); document.write( "Take the log of both sides:
\n" ); document.write( "x = [log3.7599]/[log1.0278]
\n" ); document.write( "x = 48.3 years
\n" ); document.write( "===================\r
\n" ); document.write( "\n" ); document.write( "2. The half life of a radioactive substance is ninety(90) day. How many days will it take for seventy-five percent (75%) of the substance to decay?
\n" ); document.write( "0.75Ao = Ao(1/2)^(t/90)
\n" ); document.write( "(1/2)^(t/90) = 0.75
\n" ); document.write( "Take the log and solve for \"t\":
\n" ); document.write( "(t/90) = [log0.75]/[log(1/2)]
\n" ); document.write( "t/90 = 0.4150
\n" ); document.write( "t = 37.4 minutes
\n" ); document.write( "=========================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( " \n" ); document.write( "
\n" );