Answer:
15 black marbles
Step-by-step explanation:
So its. A ratio (basically a fraction)
3/2
we add them up so we know how much marbles but not which kind
so we get 5
now we know for every 5 batches there is 3 black and 2 red
so we divide 25/5 to get 5
now we know there are 5, 5 batches of black ad red marbles.
now black is 3 of them so we multiply 5(3) which is 15
Now red is 2 of them so we multiply 5(2). Which is 10
now to check, if we add them up, they equal to 25 which is correct.
basically add the fraction, divide that by the original number, time the quotient by each number in the fraction.
38 - 171 divided by 19 times 2
The coefficient is 2 because it is being multiplied by the p.
