Question: In a follow up survey of the same kids two years later, it was found that all the kids were now in school. Of the kids who were not in school earlier, in one region, 25% were in G now, whereas the rest were enrolled in P; in the second region, all such kids were in G now; while in the third region, 50% of such kids had now joined G while the rest had joined P. As a result, in all three regions put together, 50% of the kids who were earlier out of school had joined G. It was also seen that no surveyed kid had changed schools.
Explanation:
Consider the final table obtained in the solution to the first question.
Now since 50% of 2400 i.e. 1200 kids were in G now and from one of the regions all had joined G, obviously it cannot ne from W, since in O in W region, there are 1500 kids. Also, if 25% of the kids from ‘O’ in the W region
i . e . , 25 100 × 1500 = 375
it would mean that the 50% kids who joined G would have to be from NE or S region, which would mean that the total number of kids who joined G from O would never total upto 1200. So 50% of the kids from O in the W regions join G which means
50 100 × 1500 = 750
kids from W region ‘O’join G. Now 100% of the kids from the NE, region in O (i.e., 600 kids) cannot join G as then total of the kids from the NE region in O (i.e., 600 kids) cannot join G as then total of the kids from ‘O’ region joining G region would exceed 1200.
This implies that 25% of the kids from the NE region in O
i . e . , 25 100 × 600 = 150 kids
join G which means that 100% of the kids from S region in
'O' i . e . , 100 100 × 300 = 300
So, the number of kids from ‘NE’, ‘W’ and ‘S’ region in O joining G is 150, 750 and 300 respectively and this totals upto 1200 kids, which is the required number of students joining G from O.
Number of kids now in G in W region is 5250 + 750 = 6000.
Hence, option (a).