Question

After the change process, which of the following is the correct sequence of number of students in the six electives E1 to E6?

• A. 19,76,21,45,60
• B. 19,76,78,22,45,60
• C. 18,76,79,23,43,61
• D. 18,76,79,21,45,61

Answer 1

The correct option is D 18,76,79,21,45,61

STEP I:
Given that after change, E2 is 30 more than before. E2 before was at least 46. E2 (after was 76). So, E2 before must have been 76-30 =46. That indicates that the two empty cells can be filled as 0 each across the row E2. Hence, the table will be as follows (after this condition).

STEP II:
Given that before change E1 = E4 + 6. Now, E1 (before) = 31. Further, E4 (before) must be more than 23 (3 + 2 + 14 + 4 + data in two empty cells). That indicates, the two empty cells across E4 must be 1 and 1. So, after this step, the cells can be filled up as follows.

STEP III:
Given that after change, E1 = E4 -3. It is to be noted that E1 (afterwards) can be at least 16 and at most 18. E4 (column) cannot be 20, as in that case, the total number of zeroes will cross 4. E4 must be 21. So, that E1 (afterwards) will be 18. This indicates, there must be 3 zeroes in E4 and one entry as “1” in the column E4. All other entries will be “1”.

After the change process, correct sequence of number of persons in electives E1 to E6 is as shown below:- 18, 76, 79, 21, 45 and 61.