Answer:
9 blue marbles and 1 red or yellow marble
Step-by-step explanation:
Since the bag contains 6, 2, and 2 quantity of blue, red and yellow marbles respectively. It means the bag contains a total of 10marbles.
So ideally, the probability of picking a blue marble at random will be 6/10 i.e. 6blue marbles/ total number of marbles
Now, in order to have the probability of a blue marble being randomly picked out to be 75%,
We have to first convert the percentage to fraction= 75% means 75/100 , we divide both numerator and denominator by 5
We have 15/20, which means 15 blue marble / 20 total marbles
To get 75% probability, we have to have 20 total marbles by adding an additional 10. Since we are working on the probability of a blue marble being picked, it means we must add 15 - 6 = 9 blue marbles
Since 10 additional marbles must be added in total, 9 blue marbles has already been added, so we are left with 1
The 1 marble can either be a red or yellow marble.
In total we have, 10(9 blue, 1 red/yellow) + 6blue + 2red + 2yellow = 20total marbles
Probability of picking a blue marble will be, 9+6= 15 blue marbles/20 total marbles i.e 75%
