A bag contains 12 pencils, 3 sharpeners and 7 pens. What is the probability of drawing a pencil from the bag?

A bag contains 8 red pencils and 5 black pencils. What is the probability of getting a yellow pencil when one pencil is drawn at random?

A bag contains 10 pencils, 15 pens, 20 markers, 25 sketch pens. What is the prob ability of getting (i) a pencil (ii) a pen (iii) neither a pen nor a pencil (iv) not a marker if one of them is selected randomly?

A box contains 8 red pencils and some blue pencils. If the probability of drawing a blue pencil is three times of a red pencil, then the number of blue pencils in the bag are:

A bag contains 5 red balls and some blue balls. If the probability of drawing a blue ball from the bag is thrice that of drawing a red ball, then find the number of blue balls in the bag.

A bag contains 15 white and some black balls. If the probability of drawing a black ball from the bag is thrice that of drawing a white ball find the number of black balls in the bag.

A bag contains 15 white and some black balls. If the probability of drawing a black ball from the bag is thrice that of drawing a white ball, find the number of black balls in the bag.

A bag contains 10 blue balls and 12 yellow balls. Another contains 15 blue balls and 7 yellow balls. What is the probability of getting a yellow ball from the first bag?

A bag contains 10 blue balls and 12 yellow balls. Another contains 15 blue balls and 7 yellow balls. What is the probability of getting a yellow ball from the second bag?

A bag contains 3 red,4 white and 7 black balls.The probability of drawing a red or a black ball is