Question

A bag contains 6 blue balls & some white balls. if the probability of drawing a blue ballfrom the bag is 3/5 than the no. of white ball is​

Answer 1

just replace red with blue and blue with white...

Answer

Let the number of white balls =x∴ total number of balls =(6+x)

P (drawing a blue ball) = 6+x

∴P (drawing a white ball) =( 6+x )

∴ 6+x =2( 6+x )

∴ 6+x = 6+x12

12(6+x)=x(6+x)

∴72+12x=6x+x

2

∴x

2

−6x−72=0

∴(x−12)(x+6)=0

∴x=12

or x=−6(not possible)

∴ The number of white balls =12

Answer 2

Answer:

No. of red balls =n(R)=6

Let, no. of blue balls be x, n(B)=x

Total no. of balls in bag=n(T)=6+x

We know that, Probability P(Event) =

(Total no.of possible outcomes)

(No.of favorable outcomes)

Probability of drawing a red ball, P(R)=

6+x

n(R)

Probability of drawing a blue ball, P(B)=

6+x

n(B)

Given,

Probability of drawing a blue ball from the bag is twice that of a red ball

i.e., P(B)=2×P(R)

6+x

n(B)

=2×

6+x

n(R)

x=2×6

n(B)=x=12

Total no. of balls in bag=n(T)=6+x=6+12=18.