JJK Ltd. invited applications for issuing 50,000 equity shares of Rs. 10 each at par. The amount was payable as follows: On Application: Rs. 2 per share. On Allotment: Rs. 4 per share. On First and Final Call: Balance Amount. The issue was over-subscribed three times. Applications for 30,000 shares were received.

Here's how we can solve this problem step-by-step:

1. Calculate the total number of shares applied for:
The issue was oversubscribed three times, meaning applications were received for three times the number of shares offered. Therefore, the total number of applications received was 50,000 shares * 3 = 150,000 shares.

2. Determine the allotment:
Only 50,000 shares were to be issued. Applications for 150,000 shares were received. Therefore, the allotment will be done pro-rata based on the number of shares applied for.
The allotment ratio would be 50,000 shares / 150,000 applications = 1/3
This means that for every 3 shares applied for, only 1 share will be allotted.

3. Calculate the allotment for 30,000 applications:
An applicant who applied for 30,000 shares will receive 30,000 shares * (1/3) = 10,000 shares.

4. Calculate the amount payable:

• Application Money: 10,000 shares * Rs. 2/share = Rs. 20,000
• Allotment Money: 10,000 shares * Rs. 4/share = Rs. 40,000
• First and Final Call: The balance amount per share is Rs. 10 - Rs. 2 - Rs. 4 = Rs. 4. Total amount due for first and final call is 10,000 shares * Rs. 4/share = Rs. 40,000

5. Total amount payable:
Total amount payable by the applicant is Rs. 20,000 + Rs. 40,000 + Rs. 40,000 = Rs. 100,000

Therefore, an applicant who applied for 30,000 shares will be allotted 10,000 shares and will have to pay a total of Rs. 100,000.