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Dialing a telephone number, a man forgot...

Dialing a telephone number, a man forgot the last two digits and remembering only that they are different . He dialled the number at random. The probability of the number dialled correctly is :

A

`1/2`

B

`1/45`

C

`1/72`

D

`1/90`

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The correct Answer is:
D
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MODERN PUBLICATION-UNIT TEST PAPER NO. 6 (THREE - DIMENSIONAL GEOMETRY, VECTORS & PROBABILITY)-Select the correct answer
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