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<?php $a = "3.11"; $b = "2.9"; $c = "3.10"; $d = "1.11"; $arr1 = explode(".", $a); $arr2 = explode(".", $b); $arr3 = explode(".", $c); $arr4 = explode(".", $d); $y = $arr1[0] + $arr2[0] + $arr3[0] + $arr4[0]; // calculate years If($arr1[1] + $arr2[1] + $arr3[1] + $arr4[1] >=12) $y += floor(($arr1[1] + $arr2[1] + $arr3[1] + $arr4[1])/12); // add one if months is more than 11 $m = ($arr1[1] + $arr2[1] + $arr3[1] + $arr4[1])%12; // modulo calculate months Echo $y . " " . $m;

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