Assignment
Class Exercise-13 Permutation & Combination 1. If 56Pr + 6 : 54Pr + 3 = 30800. then r is (a) 39 (b) 41 (c) 28 (d) 43 2. If nCx = 56 and nPx = 336, then n is equal to (a) 7 (b) 8 (c) 6 (d) 10 3. In how many ways the letters of the word RAINBOW be arranged? (a) 5040 (b) 4050 (c) 8040 (d) 6050 4. How many numbers greater than 50000 can be formed with the digits 4, 5, 6, 7 and 8 if no digit being repeated (a) 96 (b) 256 (c) 218 (d) 126 5. In how many ways can 10 soldiers stand in two rows having 5 soldiers in each row? (a) 3628800 (b) 7257600 (c) 35400 (d) 985000 6. If the maximum number of trials required to open all locks when three are n locks and n keys is 105, then n = (a) 13 (b) 14 (c) 35 (d) 20 7. How many arrangements can be made out of the letters of the word COMMITTEE, taken all at a time, such that the four vowels do not come together? (a) 12600 (b) 45600 (c) 43200 (d) 216 8. How many different words can be made with the letters of the word NAINITAL such tha...