karma.d.ghost

Problem 2 Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ... By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms. Solution1:  <?php $fib1 = 1; $fib2 = 2; $temp = 0; $sum =0; while($temp<=4000000){ $temp = $fib2; $sum = ($temp%2==0) ? ($sum + $temp) : $sum ; $temp = $fib1 + $fib2; $fib1 = $fib2; $fib2 = $temp; } echo $sum;