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1. 10 students are to be seated in two rows equally for the Mock test in a room. There are two sets of papers, Code A and Code B. each of two rows can have only one set of paper but different that from other row. In how many ways these students can be arranged ?
Remaining 5 will be seated in,
= 5C5 ways
Students of each row can be arranged as,
= 5! × 5! ways
Two sets of paper can be arranged themselves in,
= 2! ways
Thus, Total arrangement,
= 10C5 × 5! × 5! × 2
= 7257600
Solution:
5 students can be seated out of 10 students in 10C5 waysRemaining 5 will be seated in,
= 5C5 ways
Students of each row can be arranged as,
= 5! × 5! ways
Two sets of paper can be arranged themselves in,
= 2! ways
Thus, Total arrangement,
= 10C5 × 5! × 5! × 2
= 7257600