Sum of multiples of A and B less than N | PHP program to find the sum of all multiples of A and B below N ; Function to find sum of AP series ; Number of terms ; Function to find the sum of all multiples of A and B below N ; Since , we need the sum of multiples less than N ; common factors of A and B ; Driver code
< ? php function __gcd ( $ a , $ b ) { if ( $ b == 0 ) return $ a ; return __gcd ( $ b , $ a % $ b ) ; } function sumAP ( $ n , $ d ) { $ n = ( int ) ( $ n / $ d ) ; return ( $ n ) * ( 1 + $ n ) * $ d / 2 ; } function sumMultiples ( $ A , $ B , $ n ) { $ n -- ; $ common = ( int ) ( ( $ A * $ B ) / __gcd ( $ A , $ B ) ) ; return sumAP ( $ n , $ A ) + sumAP ( $ n , $ B ) - sumAP ( $ n , $ common ) ; } $ n = 100 ; $ A = 5 ; $ B = 10 ; echo " Sum = " ? >