// THIS IS THE PREFERRED ANSWER
public boolean squirrelPlay(int temp, boolean isSummer) {
  if (isSummer) {
    return 60 <= temp && temp <= 100;
  }
  else {
    return 60 <= temp && temp <= 90;
  }
}

public boolean squirrelPlay(int temp, boolean isSummer) {
  if (isSummer) {
    if (60 <= temp && temp <= 100) {
      return true;
    }
    else {
      return false;
    }
  }
  else {
    if (60 <= temp && temp <= 90) {
      return true;
    }
    else {
      return false;
    }
  }
}

public boolean squirrelPlay(int temp, boolean isSummer) {
  int upper = 90;
  if (isSummer) {
    upper = 100;
  }
  return 60 <= temp && temp <= upper;
}

public boolean squirrelPlay(int temp, boolean isSummer) {
  return 60 <= temp && temp <= (isSummer ? 100 : 90);
}