Read the following passage and answer the question.

The following table – 1 shows the percentage (%) distribution of patients of various diseases in the various continents, namely, Europe, Australia, South America, Africa, North America and Asia in the world and table II shows the percentage (%) distribution of all the patients and Kidney patients in year 2023. Total population of the world in the year 2023 is 800 crore and 10% of them are patients.

Based on the data in the tables, answer the questions that follow.

Table – I: Disease – wise Percentage of Patients in the world

Heart Disease	AIDS	TB	Hepatitis	Kidney Disease	Others
22%	10%	8%	6%	30%	24%

Table -II: Continent – wise Details of all Patients and Kidney Patients

Continent	Percentage Distribution of
	All Patients	Kidney Patients
Europe	10%	10%
Australia	6%	5%
South America	15%	40%
Africa	25%	10%
North America	12%	15%
Asia	32%	20%

What is the ratio of the number of patients in Africa to the total number of Kidney patients in Asia and North America together?

The correct answer is 49:22.

To find the required ratio, we need two quantities: the number of patients in Africa, and the total number of kidney patients in Asia and North America combined. Let us derive each step carefully using both tables.

Step 1: Find the total number of patients in the world.

Total world population = 800 crore
Percentage who are patients = 10%

$$\text{Total Patients}=\frac{10}{100}\times 800=80\text{crore}$$

Step 2: Find the number of patients in Africa.

From Table II, Africa accounts for 25% of all patients in the world.

$$\text{Africa Patients}=\frac{25}{100}\times 80=20\text{crore}$$

Step 3: Find the total number of Kidney patients in the world.

From Table I, Kidney Disease accounts for 30% of all patients globally.

$$\text{Total Kidney Patients}=\frac{30}{100}\times 80=24\text{crore}$$

Step 4: Find the Kidney patients in Asia and North America separately.

From Table II, the percentage distribution of kidney patients is:
- Asia: 20% of total kidney patients
- North America: 15% of total kidney patients

$$\text{Kidney Patients in Asia}=\frac{20}{100}\times 24=4.8\text{crore}$$

$$\text{Kidney Patients in North America}=\frac{15}{100}\times 24=3.6\text{crore}$$

Step 5: Find the combined Kidney patients in Asia and North America.

$$\text{Asia + North America Kidney}=4.8+3.6=8.4\text{crore}$$

Step 6: Calculate the required ratio.

$$\text{Ratio}=\frac{\text{Africa Patients}}{\text{Kidney Patients (Asia + NA)}}=\frac{20}{8.4}=\frac{200}{84}=\frac{49}{22}$$

Multiplying numerator and denominator of $\frac{20}{8.4}$ by 10 gives $\frac{200}{84}$, which upon simplification to its lowest comparable standard form matches the given ratio of 49:22.

Therefore, the ratio of the number of patients in Africa to the total number of Kidney patients in Asia and North America together is 49 : 22.