Consider the following fictitious statistics about KZN province:

In KZN, [tex]\frac{2}{3}[/tex] of the adult men are married to [tex]\frac{3}{5}[/tex] of the adult women. Assume that no one is married to more than one other person and that there are at least 300 adult men in KZN.

Using the unique factorization theorem, what is the least possible number of adult men in the province?



Answer :

To find the least possible number of adult men in KZN, we start by establishing the relationship between the number of adult men and adult women based on the given information:

1. According to the problem, [tex]\(\frac{2}{3}\)[/tex] of the adult men are married to [tex]\(\frac{3}{5}\)[/tex] of the adult women.
2. Let [tex]\(m\)[/tex] represent the number of adult men and [tex]\(w\)[/tex] represent the number of adult women.
3. The relationship translates to:
[tex]\[ \frac{2}{3} \cdot m = \frac{3}{5} \cdot w \][/tex]
4. Simplifying this equation, we get:
[tex]\[ 2m = \frac{9}{5}w \][/tex]
Multiplying both sides by 5 to clear the fraction:
[tex]\[ 10m = 9w \][/tex]
5. Solving for [tex]\(w\)[/tex] in terms of [tex]\(m\)[/tex], we have:
[tex]\[ w = \frac{10}{9}m \][/tex]

We need the number of women, [tex]\(w\)[/tex], to be an integer. Starting with at least 300 men, we check if there is an integer value for [tex]\(w\)[/tex] corresponding to an integer [tex]\(m \geq 300\)[/tex]:

1. If we set [tex]\(m = 300\)[/tex]:
[tex]\[ w = \frac{10}{9} \cdot 300 = \frac{3000}{9} \approx 333.33 \quad \text{(not an integer)} \][/tex]

Since [tex]\(333.33\)[/tex] is not an integer, [tex]\(m = 300\)[/tex] is not a solution. We increment [tex]\(m\)[/tex] until we find the smallest [tex]\(m\)[/tex] making [tex]\(w\)[/tex] an integer:

2. Increasing [tex]\(m\)[/tex] step by step:
3. If we set [tex]\(m = 301\)[/tex]:
[tex]\[ w = \frac{10}{9} \cdot 301 = \frac{3010}{9} \approx 334.44 \quad \text{(not an integer)} \][/tex]
4. If we set [tex]\(m = 302\)[/tex]:
[tex]\[ w = \frac{10}{9} \cdot 302 = \frac{3020}{9} \approx 335.56 \quad \text{(not an integer)} \][/tex]
5. Continuing this process:
6. We find that when [tex]\(m = 306\)[/tex]:
[tex]\[ w = \frac{10}{9} \cdot 306 = \frac{3060}{9} = 340 \quad \text{(an integer)} \][/tex]

Thus, the least possible number of adult men in the province, ensuring that the number of adult women is an integer, is:

[tex]\[ \boxed{306} \][/tex]