Six cards and six envelopes are numbered 1, 2, 3, 4, 5 and 6
MATHEMATICS · Numerical · CBSE · Mathematics · Permutations and Combinations · Permutations and Combinations
Problem
Six cards and six envelopes are numbered 1, 2, 3, 4, 5 and 6. The cards are to be placed in envelopes so that each envelope contains exactly one card, no card is placed in the envelope bearing the same number, and card 1 is always placed in envelope 2. Find the number of ways this can be done.