Question

A bag contain white green and red balls at random in a bag if the probability of a white ball is 3/10 and of black ball is2/5find the of red balls if the bag has 20 black balls find the number of balls in the bag

Answer 1

( I have taken black ball as green ball, because you have written there are three coloured ball green,white, red in the bag)


Probability of green ball= 2/5
= 20/50
hence,
total number of green balls are 20 (given)
total number of balls in bag are 50

Probability of white balls= 3/10
= 15/50
hence,
total number of white ball are 15

Probability of red balls= (50-15+20)/50
=15/50
total number of red balls are 15