Choose the correct answer

Ajay had a box containing $20$ red marbles and $30$ green marbles. Rajesh gave him $15$ red and $5$ green marbles to put in the box. Then the probability of picking a red marble from the box is:

Note: duplicate option is there; so some changes in the options

 

A pair of dice is rolled simultaneously. If the simplest form of probability of getting a greater number on second dice is $\frac{a}{b}$, then find the value of $a+b$.

A bag contains one ball known to be either black or white. A black ball is put in and the bag is shaken and a ball is drawn out. What is the probability of the remaining ball being black, if the ball drawn is white ?

On a wall clock, what is the probability that the hour hand will pass through number $6$ once in $12$ hours?

Anjula and Parul were playing a board game. On the board, $16$ squares of equal size are drawn and some of them are shaded. Anjula and Parul are throwing the dice turn by turn and following the instructions of the game.

If Anjula throws a dice first, the probability that the dice falls on a shaded square is $x$, and the probability that the dice fall on a white square is $y$.

What is difference of $x$ and $y$?

Reema is playing with an ordinary die. She throws the die twice and every time notes down the product of the two scores which appeare:

First, fill the above table and then find the probability that the product of the two scores is an odd number.

Two dice are rolled simultaneously. Find the probability of getting the sum as $7$

An ordinary dice is thrown twice and the product of the two scores is found.

Find the probability that the product of the two scores is an even number.