Question

A box has 20 Red balls and some black balls if the probabiliti is 3/8 that a ball selected at random from the box is black then find the number of black balls? ​

Answer 1

Step-by-step explanation:

of red ball) =1−(103+52)

                       =1−(3+104)

                       =1−107=1010−7

P (of red ball) =103

No. of black balls =totalno.ofballs20

    52=totalno.ofballs20                          

⇒50 = total no. of balls 

Answer 2

Answer:

no. of red balls=1-(103+52)

=1-(3+104)

=1-107-1010

P of red balls=103

no. of black balls=total no. of ball

=20

50=total no. of ball

=20

=>50 is the total no. of balls