// PR Bab 16, soal 2 -- pembahasan.
//
// a. 4 * 5 * 5           = 100
// b. 900 - 8 * 9 * 9     = 252
// c. 250 + 166 - 83      = 333
// d. 4 * 3 * (2 + 1)     = 36

#include <iostream>
using namespace std;

int main() {
    // a. semua digit genap
    int a = 0;
    for (int n = 100; n <= 999; n++) {
        int r = n / 100, p = (n / 10) % 10, s = n % 10;
        if (r % 2 == 0 && p % 2 == 0 && s % 2 == 0) a++;
    }
    cout << "a: " << a << " (rumus 4*5*5 = " << 4 * 5 * 5 << ")\n";

    // b. minimal satu angka 7
    int b = 0;
    for (int n = 100; n <= 999; n++) {
        int r = n / 100, p = (n / 10) % 10, s = n % 10;
        if (r == 7 || p == 7 || s == 7) b++;
    }
    cout << "b: " << b << " (rumus 900 - 8*9*9 = " << 900 - 8 * 9 * 9 << ")\n";

    // c. habis dibagi 4 atau 6
    int c = 0;
    for (int n = 1; n <= 1000; n++)
        if (n % 4 == 0 || n % 6 == 0) c++;
    cout << "c: " << c << " (rumus 250 + 166 - 83 = " << 250 + 166 - 83 << ")\n";

    // d. paket menu, hidangan penutup boleh tidak diambil
    int d = 0;
    for (int makanan = 0; makanan < 4; makanan++)
        for (int minuman = 0; minuman < 3; minuman++)
            for (int penutup = 0; penutup < 3; penutup++)   // 2 pilihan + tidak ambil
                d++;
    cout << "d: " << d << " (rumus 4*3*3 = " << 4 * 3 * 3 << ")\n";
    return 0;
}