NDA 2026 · PYQ · Probability / Permutations · easy
A 4-digit number is selected at random formed by using the digits 0, 1, 2, 3 and 4 (where repetition of digits is not allowed). What is the probability that the number selected does not contain zero at any position?
A.0·12
B.0·25✓ Correct
C.0·375
D.0·45
Explanation
Total 4-digit numbers without repetition = 96. Numbers without 0 use digits from {1,2,3,4}, all 4 digits: 4! = 24. Probability = 24/96 = 1/4 = 0.25.
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