Question

a) How many English words of 3 bit strings are there that either starts with an A or ends with Z.
b) A biased die is rolled. The probability of getting 4 and 5 is twice as compared to other so what is the probability of having even number on dice.
Please solve these completely.

Answer 1

a) There are 26 letters in total as the string is 3 bit

So number of 3 bit string with A in the beginning is

Number of 3 bit string which ends with Z is

Also there are 26, 3 bit strings which starts with A and with Z, like ABZ, AZ,.....

Hence the required number is

b) When die is rolled, 4 and 5 can't appear at the same time.

So correct the question