Write the sample space in tossing two coins simultaneously.

A box contains $8$ black, $7$ white and $6$ yellow balls in it. One ball is taken out from the box at random. What is the probability that the ball taken out is:

a) Yellow

b) Not a black

c) White

The probability of an impossible event is 

A circle is drawn in a triangular board as shown in the figure.

If a ball is thrown to the board, then find the probability of the ball that collide in the interior of the circle.

One card is drawn from a well-shuffled deck of $52$ cards. Find the probability of getting a king of red colour.

A box contains some green and blue balls. $7$ red balls are put into it. Now the probability of getting a red ball from the box is $\frac{7}{24}$ and that of the blue ball is $\frac{1}{3}$. How many balls are there in the box?

A box contains some green and blue balls. $7$ red balls are put into it. Now the probability of getting a red ball from the box is $\frac{7}{24}$ and that of the blue ball is $\frac{1}{3}$. How many balls are blue?

One card is drawn from a well-shuffled deck of $52$ cards. Find the probability of getting a spade.

An integer is chosen at random between $1 \text{and} 100$. Find the probability that it is divisible by $8$.