At a management school, the oldest 10 dorms, numbered 1 to 10

At a management school, the oldest 10 dorms, numbered 1 to 10, need to be repaired urgently, The following diagram represents the estimated repair costs (in Rs. Crores) for the 10 dorms. For any dorm, the estimated repair cost (in Rs. Crores) is an integer. Repairs with estimated cost Rs. 1 or 2 Crores are considered light repairs, repairs with estimated cost Rs. 3 or 4 are considered moderate repairs and repairs with estimated cost Rs. 5 or 6 Crores are considered extensive repairs.

Further, the following are known:

  1. Odd-numbered dorms do not need light repair; even-numbered dorms do not need moderate repair and dorms, whose numbers are divisible by 3, do not need extensive repair.
  2. Dorms 4 to 9 all need different repair costs, with Dorm 7 needing the maximum and Dorm 8 needing the minimum.

1. Which of the following is NOT necessarily true?

  1. Dorm 1 needs a moderate repair
  2. Dorm 5 repair will cost no more than Rs. 4 Crores
  3. Dorm 7 needs an extensive repair
  4. Dorm 10 repair will cost no more than Rs. 4 Crores

2. What is the total cost of repairing the odd-numbered dorms (in Rs. Crores)?

Suppose further that:

  1. 4 of the 10 dorms needing repair are women's dorms and need a total of Rs. 20 Crores for repair.
  2. Only one of Dorms 1 to 5 is a women's dorm.

3. What is the cost for repairing Dorm 9 (in Rs. Crores)?

4. Which of the following is a women's dorm?

  1. Dorm 2
  2. Dorm 5
  3. Dorm 8
  4. Dorm 10

Answers

  1. D
  2. 19
  3. 3
  4. D

From the data, there are 2 dorms which require Rs.1 crore, 1 dorm which requires Rs.2 crore, 3 dorms which require Rs.3 crore, 1 dorm which requires Rs.4 crore, 1 dorm which requires Rs.5 crore and two dorms which require Rs.6 crore. Hence the total amount needed is Rs.34 crore.

Dorms 4 to 9 have different repair costs. Dorm 7 needs the maximum and Dorm 8 needs the minimum. From the other conditions given, we have the following table with partial data.

1. Going by the options, Dorm 1 needs a moderate repair is possibly true. Dorm 5 not needing more than Rs.4 crore is true. Hence Dorm 10’s repair not costing more than Rs.4 crore is not necessarily true as it may require Rs.6 crore or Rs.1 crore.

2. The total cost for the odd numbered dorms are 3 + 3 + 3 (or) 4 + 6 + 4 (or) 3 i.e. Rs.19 crore.

Additional data

4 of the 10 dorms are women's dorms which need Rs.20 crore for repairs. Also from 1 to 5 there is only one women's dorm. This is possible with repairing costs Rs.6, Rs.6, Rs.5 and Rs.3 crore. Among the first 5, dorm 4 should be women's dorm. Rs.6 cr dorms can only be dorm 7 and dorm 10. Rs.3 crore can be from dorm 1, 3, 5 or 9. But 1, 3 or 5 are not women's dorm. So it has to be dorm 9.

3. From the above, the repair cost for dorm 9 is Rs.3 crore.

4. From the above, dorm 10 should be women's dorm.