CAT 1995QA Question 21

BasicsEasy

If a 4 digit number is formed with digits 1, 2, 3 and 5. What is the probability that the number is divisible by 25, if repetition of digits is not allowed?

Answer & solution

Correct answer: 1 12

  • 112

  • B

    14

  • C

    16

  • D

    None of these

Solution

Total number of four-digit numbers that can be formed = 4!.
If the number is divisible by 25, then the last two digits are 25.
So the first two digits can be arranged in 2! ways.
Hence, required probability = 2!4!=112.

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CAT 1995 QA Q21: If a 4 digit number is formed with digits 1, 2, 3 and 5. What is the probability that the number is divisible — Solution | TheCATExam