Read the following table carefully and answer the question that follows. The…

To find how many members of a group did NOT do something, first work out the group's total size and how many DID do it -- the difference between the two is the answer. In this table, percentages describe different bases (girls as a share of the whole department vs. each gender's share of the donor pool), so each percentage must be applied to its own correct base before the figures can be combined.

1. In department A, the table gives 48 as the number of boys who donated blood, and 40% as the girls' share of the total donors -- so boys make up the remaining 60% of the donor pool.

2. Total blood donors in department A = 48 divided by 60% = 80. So the number of girls who donated = 80 minus 48 = 32.

3. The question states that ALL the girls in department A donated blood, so the 32 girl donors just found ARE the department's entire girl population.

4. Girls are 25% of department A's total strength (given in the table), so the department's total strength = 32 divided by 25% = 128.

5. Boys in department A = 128 minus 32 = 96.

6. Since every girl has already donated, anyone who has NOT donated blood in department A must be a boy. Boys who donated = 48 (given), so boys who did not participate = 96 minus 48 = 48.

Cross-check: the total number of students who did not donate blood in department A = department total minus total donors = 128 minus 80 = 48. Because all the girls are already among the donors, this entire non-donor group is made up of boys -- the same 48 obtained above, confirming the result.

So 48 boys in department A did not participate in the blood donation camp.