There are 25 red, blue, yellow and
green marbles in a bag. Four of the marbles
are blue and the probability of selecting a blue
or green marble at random is 40%. Write
and solve an equation to determine the
number of green marbles in the bag
prob(blue or green) = (4 + G)/25 = 40/100
4+G = 25(40)/100 = 10
G = 6
To solve this problem, we need to set up an equation based on the given information.
Let's represent the number of green marbles as 'x'.
We are told that the probability of selecting a blue or green marble randomly is 40%. This means the number of blue and green marbles combined must be 40% of the total number of marbles, which is 25.
Since we know there are four blue marbles, the number of green marbles can be represented as (0.40 * 25) - 4, because we need to subtract the number of blue marbles from the total number of marbles that are blue or green.
Hence, the equation becomes:
0.40 * 25 - 4 = x
Now we can solve for x.
0.40 * 25 - 4 = x
10 - 4 = x
6 = x
So, there are 6 green marbles in the bag.