How do I calculate the percentage of the right number of answers?

Question

Good, I think I have already achieved what I wanted to thank everyone my only doubt is whether a new number is generated every time the user enters a new guess,here is the new code:

System . out . println("Indique um valor minimo");
        int min = scanner.nextInt();
        System . out . println("Indique um valor máximo");
        int max = scanner.nextInt();
        System . out . println("Vão agora ser gerados números entre " + min + " e " + max);
        double rand = Math.random();
        int entreMinEMax =(int) (min +(max - min + 1) * rand);
        int palpites = 0;
        int acertou = 0;
        int errou = 0;

        do
        {
            System . out . println("Indique o seu palpite:");
            int palpite = scanner.nextInt ();
            if (palpite == entreMinEMax)
            {
                acertou++;
            }else
            {
              errou++;  
            }
            palpites++;
        }while(palpites<10);

        System . out . println ("Acertou " + acertou + "     "   +  (acertou/10)*100 + "%");
        System . out . println ("Errou " + errou + "     "   +  (errou/10)*100 + "%");

Answer 1

For the success test you are taking, only one correct attempt will be accounted for due to the break that has in the for. This makes the calculation have to be done only considering the failed attempts previously.

You can make the calculation as follows:

sucesso = (total_tentativas - tentativas_falhadas) / total_tentativas

Example in the code:

for(int resposta=0; resposta < 10; resposta++)
{
    System . out . println("Indique o seu palpite:");
    int palpite = scanner.nextInt ();

    if(palpite == entreMinEMax)
    {
        double sucesso = (10.0 - resposta) / 10; //calculo de sucesso
        System.out.println("Parabéns!!Acertou!!");
        System.out.println("Percentagem de sucesso: " + (sucesso*100) + "%");
        break;
    }
}

In the calculation is done 10.0 - resposta because the variable resposta indicates the amount of failed attempts previously, as each time a new iteration is done because the user failed.

See the example in Ideone