document.write( "Question 1206057: Consider a population that grows according to the recursive rule Pn=Pn-1+35, with initial population Po=20.
\n" ); document.write( "
\n" ); document.write( "Then:
\n" ); document.write( "
\n" ); document.write( "P1 = __________
\n" ); document.write( "P2 = _________
\n" ); document.write( "
\n" ); document.write( "Find an explicit formula for the population. Your formula should involve n (use lowercase n)
\n" ); document.write( "
\n" ); document.write( "Pn= __________
\n" ); document.write( "
\n" ); document.write( "Use your explicit formula to find P100
\n" ); document.write( "
\n" ); document.write( "P100 =__________
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #843255 by ikleyn(52781) $\"\"$ $\"About$

You can put this solution on YOUR website!
.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "        Be careful :   this problem is a trap.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "        The trap is that this sequence is SPECIAL :   it IS an arithmetic sequence,
\n" ); document.write( "        but starts from the zeroth term 20.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "        Therefore, the formula for the n-th term must be modified.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "

\r\n" );
document.write( "The standard formula  = 20 + (n-1)*35  does    work now - it should be modified.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    +---------------------------------------------+\r\n" );
document.write( "    |   The correct formula is P[n] = 20 + n*35   |\r\n" );
document.write( "    +---------------------------------------------+\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Again, your correct explicit formula is   = 20 + n*35.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "You can    it:   = 20 + 1*35 = 20 + 35 = 55.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "In particular,   = 20 + 100*35 = 3520.\r\n" );
document.write( "

\r
\n" ); document.write( "\n" ); document.write( "Solved.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The solution and the calculations by @MathLover1 are INCORRECT and lead you to WRONG answer.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "----------------\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "For introductory lessons on arithmetic progressions see \r
\n" ); document.write( "\n" ); document.write( "    - Arithmetic progressions\r
\n" ); document.write( "\n" ); document.write( "    - The proofs of the formulas for arithmetic progressions \r
\n" ); document.write( "\n" ); document.write( "    - Problems on arithmetic progressions \r
\n" ); document.write( "\n" ); document.write( "    - Word problems on arithmetic progressions\r
\n" ); document.write( "\n" ); document.write( "in this site.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );