Statement:
Eighty percent of the employees of X Ltd. earn more than Rs. 5000 per month. Seventy percent of employees of X Ltd. work as supervisors.
Conclusions:
I. All the supervisors earn more than Rs. 5000 per month.
II. Less than 100% of the supervisors earn more than Rs.5000 per month.
Answer: C
The given statement tells us that 80% of the employees of X Ltd earn above Rs. 5000 per month. It also tells us that 70% of the employees work as supervisors. From this we know that 20% of the employees earn Rs. 5000 or less. If this 20% are all supervisors then we can say that at least 50% of the supervisors earn more than Rs. 5000 per month. If none of these 20% employees are supervisors, it means that all the supervisors earn more than Rs. 5000 per month. Thus we can say that either 100% of the supervisors earn more than Rs. 5000, or conversely less than 100% of the supervisors earn more than Rs. 5000. This is exactly what conclusions I and II state, but we know that only one of them is definitely true. Hence, either I or II follows, but not both.