Multiple tasks from one if-statment

Projects Programming
5

Thanks, greatful for your reply's. Will check out these solutions.
By the way, here the sketch is "lined out".

int redPin = 3;
int yellowPin = 4;
int greenPin = 5;
int readPin = A1;
int buzzer = 12;
int readVal;
float V2;
float tr1 = 2;
float tr2 = 3.5;
float trAlarm = 5;
int delayAlarm = 10;
int delayAlarm2 = 200;

void setup() {
  Serial.begin(9600);

  pinMode(redPin, OUTPUT);
  pinMode(yellowPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(readPin, INPUT);
  pinMode(buzzer, OUTPUT);
}

void loop() {

  readVal = analogRead(readPin);
  V2 = (5. / 1023.) * readVal;

  if (V2 < tr1) {
    digitalWrite(greenPin, HIGH);
  } else {
    digitalWrite(greenPin, LOW);
  }

  if (V2 > tr2) {
    digitalWrite(greenPin, LOW);
  }
  if (V2 > tr1 && V2 < tr2) {
    digitalWrite(yellowPin, HIGH);
  } else {
    digitalWrite(yellowPin, LOW);
  }
  if (V2 > tr2) {
    digitalWrite(redPin, HIGH);
  } else {
    digitalWrite(redPin, LOW);
  }
  if (V2 == trAlarm) {
    digitalWrite(redPin, HIGH);
    delay(delayAlarm2);
    digitalWrite(redPin, LOW);
    delay(delayAlarm);
    unsigned char i;
    for (i = 0; i < 80; i++) {
      digitalWrite(buzzer, HIGH);

      delay(1);
      digitalWrite(buzzer, LOW);
      delay(1);
    }
    for (i = 0; i < 100; i++) {
      digitalWrite(buzzer, HIGH);
      delay(2);
      digitalWrite(buzzer, LOW);
      delay(2);
    }
  }
  Serial.print("potensiometer Volt er ");
  Serial.println(V2);
}