This is the cleanest code I could come up with:

    double tip = (double) tip_percent/100 * meal_cost;
    double tax = (double) tax_percent/100 * meal_cost;
    long total_cost = Math.round(meal_cost + tip + tax);
    System.out.println(total_cost);

The main complication here is getting rid of the integer division that will return zero for tip_percent/100. tip_percent is an integer. You can force a real division by having any element of the expression be a double, such as writing tip_percent/100.00 or by explicitly casting to double, which I think is more straightforward. Math.round takes a double and returns a long, so total_cost is a long. You could cast it to an int, but there is no need.

It can be all written in single expression, though not as readable:

    System.out.println(Math.round(meal_cost * (1 + (double) tip_percent / 100 + (double) tax_percent / 100)));

import java.io.; import java.math.; import java.security.; //import java.atext.; import java.util.; import java.util.concurrent.; import java.util.regex.*;

class Result {

public static void solve(double meal_cost, int tip_percent, int tax_percent) {
       double tip, tax, total_cost;
    tip = meal_cost * tip_percent/100;
    tax = tax_percent * meal_cost/100 ;
    total_cost = meal_cost + tip + tax;
    int round = (int) Math.round(total_cost);
    System.out.println(round);


}

}

public class Solution { public static void main(String[] args) throws IOException { BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

    double meal_cost = Double.parseDouble(bufferedReader.readLine().trim());

    int tip_percent = Integer.parseInt(bufferedReader.readLine().trim());

    int tax_percent = Integer.parseInt(bufferedReader.readLine().trim());

    Result.solve(meal_cost, tip_percent, tax_percent);

    bufferedReader.close();
}

}

In js this is the solution

function solve(meal_cost, tip_percent, tax_percent){ var tipValue = meal_cost / 100 * tip_percent; var taxValue = tax_percent / 100 * meal_cost; var totalCost = meal_cost + tipValue + taxValue; console.log(Math.round(totalCost)) }

""" Python3 Solution-paseed all test case"""

#!/bin/python3

import math
import os
import random
import re
import sys

#
# Complete the 'solve' function below.
#
# The function accepts following parameters:
#  1. DOUBLE meal_cost
#  2. INTEGER tip_percent
#  3. INTEGER tax_percent
#

# Write your code here

def solve():
    meal_cost=float(input().strip())
    tip_percent=int(input().strip())
    tax_percent=int(input().strip())
    percetage_cal=lambda x,y: (x*y)/100
    total_cost=round(meal_cost+percetage_cal(meal_cost,tip_percent)+percetage_cal(meal_cost,tax_percent))
    return total_cost
print(solve())

Resultado esta dando 14 (?) class Result {

double meal_cost = 12.0;
int tip_percent = 20;
int tax_percent = 8;

public static void solve(double meal_cost, int tip_percent, int tax_percent) {

    double gorjeta = (meal_cost/100)*tip_percent;
    double taxa =(tax_percent/100)*meal_cost;
    double total_custo = meal_cost + gorjeta + taxa;
    int round = (int) Math.round(total_custo);
    System.out.println(round);
}

}