A box contains 90 discs which are numbered from 1 to 90. If one disc is drawn at random from the box, find the probability that it bears a perfect square number.

AcademicMathematicsNCERTClass 10

Given:

A box contains 90 discs which are numbered from 1 to 90.

One disc is drawn at random from the box.

To do:

We have to find the probability that it bears a perfect square number.

Solution:

A box contains discs numbered \( 1,2,3,4, .., 89,90 \).

This implies,

The total number of possible outcomes $n=90$.

Perfect square numbers from 1 to 90 are $1, 4, 9, 16, 25, 36, 49, 64, 81$.

Total number of favourable outcomes $=9$.

We know that,

Probability of an event $=\frac{Number\ of\ favourable\ outcomes}{Total\ number\ of\ possible\ outcomes}$

Therefore,

Probability that the disc bears a perfect square number $=\frac{9}{90}$

$=\frac{1}{10}$

The probability that it bears a perfect square number is $\frac{1}{10}$.      

raja
Updated on 10-Oct-2022 13:26:57

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