id	title	challengeType	forumTopicId	dashedName
5900f4571000cf542c50ff6a	Problem 235: An Arithmetic Geometric sequence	5	301879	problem-235-an-arithmetic-geometric-sequence

--description--

Given is the arithmetic-geometric sequence u(k) = (900 - 3k)r^{k - 1}.

Let s(n) = \sum_{k=1 \ldots n} u(k).

Find the value of r for which s(5000) = -600\\,000\\,000\\,000.

Give your answer rounded to 12 places behind the decimal point.

--hints--

arithmeticGeometricSequence() should return 1.002322108633.

assert.strictEqual(arithmeticGeometricSequence(), 1.002322108633);

function arithmeticGeometricSequence() {

  return true;
}

arithmeticGeometricSequence();

// solution required