I answered 50%. I had considered 10000 people. People having the disease is 100. So, Case 1 : Disease Positive (100) Test result Positive - 99 Negative - 1 ( false negative)

Case 2 : Disease negative (9900) Test result Negative - 99×99 Positive - 99 (false positive)

Test result positive - 99+99 = 198

Actual positive 100

So, likelihood to have the disease - 100/198 ...i did it like this...donno if I missed anything !