int age;
printf("How old are you: ");
scanf("%d", &age);
if (age < 18) {
printf("Do you have an older sister/brother?");
} else if (age < 25) {
printf("Doing anything tonight?");
} else if (age < 35) {
printf("Do you have an younger sister/brother?");
} else if (age < 65) {
printf("Do you have a daughter/son?");
} else {
printf("Do you have a granddaughter/grandson?");
}