Jaggu can make one wooden chair in 3 days and Rabbu can make the same cair in 4 days. If they work together, in how many days will they make 14 chairs of the same kind?

Correct option is C

Given:

Jaggu can make one wooden chair = 3 days

Rabbu can make the same cair = 4 days. 

Solution:

Jaggu makes 1 chair in 3 days, so Jaggu's work rate is: 

​$$\text{Jaggu's rate} = \frac{1 \text{ chair}}{3 \text{ days}} = \frac{1}{3} \text{ chairs per day}$$

Rabbu makes 1 chair in 4 days, so Rabbu's work rate is:

​$$\text{Rabbu's rate} = \frac{1 \text{ chair}}{4 \text{ days}} = \frac{1}{4} \text{ chairs per day}$$ 

When they work together, their combined work rate is the sum of their individual rates:

​$$\text{Combined rate} = \frac{1}{3} + \frac{1}{4}$$ 

To add these fractions, we find a common denominator (which is 12): 

​$$\frac{1}{3} + \frac{1}{4} = \frac{(4+3)}{12}= \frac{7}{12}$$ 

Combined rate = $$\frac{7}{12}$$ Chairs per day

To find how many days it will take them to make 14 chairs, we divide the total number of chairs by their combined rate:

​$$\text{Time to make 14 chairs} = \frac{14 \text{ chairs}}{\frac{7}{12} \text{ chairs per day}} = 14 \times \frac{12}{7} = 24 \text{ days}$$ 

Thus, Jaggu and Rabbu will take 24 days to make 14 chairs when working together.​

13=412,14=312\frac{1}{3} = \frac{4}{12}, \quad \frac{1}{4} = \frac{3}{12}