Question

a box contains some blue balls and 30 white balls.probability of picking a blue ball is two fifths. find the number of blue balls​

Answer 1

Answer:

let the no of blue balls

p (getting a blue ball)= no of favourable outcome/total no of outcomes

2/5=x/x+30

2/5(x+30) =x

2x+60/5=x

2x+60=5x

2x-5x=-60

-3x =-60

minus to minus cancel

x=60/3

x=20

so there were 20 blue balls