Question

A coin is tossed 1000 times, if the probability of getting a tail is 3/8, how many times head is obtained?
(a) 525

(b) 375

(c) 625

(d) 725

Answer 1

The total number of trials is 1000. Let x be the number of times a tail occurs.

Let A be the event of getting a tail.

The number of times A happens is x.

Remember the empirical or experimental or observed frequency approach to probability.

If n be the total number of trials of an experiment and A is an event associated to it such that A happens in m-trials. Then the empirical probability of happening of event A is denoted byand is given by

Therefore, we have.

But, it is given that. So, we have

Hence a tail is obtained 375 times.

Consequently, a head is obtainedtimes.

So, the correct choice is (c).