Question

Using C #
Problem: "Tom is from the U.S. Census Bureau and greets Mary at her door. They have the following conversation: Tom: I need to know how old your three kids are. Mary: The product of their ages is 36. Tom: I still don't know their ages. Mary: The sum of their ages is the same as my house number. Tom: I still don't know their ages. Mary: The younger two are twins. Tom: Now I know their ages! Thanks! How old are Mary's kids and what is Mary's house number?"

The solution is 2,2,9, therefore mary's house # is 13
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This is the code i have thus far:

Console.WriteLine("What is the age of the first child");
num1 = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("What is the age of the second child");
num2 = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("What is the age of the third child");
num3 = Convert.ToInt32(Console.ReadLine());

How do I make it loop until they get the correct answer. (2,2,9) or (2,9,2) or (9,2,2)

If they get the answer wrong, I want the user keep trying again until they enter "quit"

Answer 1

Based on the given data, we can just obtain the possible solutions of their ages. We cannot exactly determine the ages.

Source Code:

using System;
class Sample {
static void Main() {
string val = Console.ReadLine();
int product = Convert.ToInt32(val);
int a,b;
bool flag = false;
//None of the ages is greater than the product.
//Let 'b' be the age of the elder one and 'a' be the age of younger ones.
//Therefore, 'b' must be greater than 'a'
for(a=1;a<=product;a++){
for(b=1;b<=product;b++){
if(a<b && a*a*b == product){
flag = true;
Console.WriteLine();
Console.WriteLine("Ages are " + a + ", " + a + " and " + b);
Console.WriteLine("Mary\'s house number is " + (2*a + b));
}
}
}
if(!flag){
Console.WriteLine("I cannot find their ages");
}
}
}

Output:

Please appreciate the solution if you find it helpful.

If you have any doubts in the solution, feel free to ask me in the comment section.