There are two sizes of red and blue marbles in a box. of the big marbles in the box, 45 are red and 3/4 are blue. the fraction of small marbles that are red is 2/5 and the fraction of small marbles that are blue is 3/5. there are 24 more small blue marbles than small red marbles. what percentage of the marbles are big marbles?

Big marbles = 45red 3/4 blue
Small marbles = 2/5 red    3/5 blue    24 more small blue mabrles than red marbles
What percentage of the marbles are big marbles

First of all lets working out the missing values: 
Big Marbles, 45 red, 3/4 blue. If 45 red is 1/4, then 135 (45*3) is 3/4.
Big Marbles, 45 red, 135 blue = 180 in total

For the small marbles, we do some logical thinking:
If red is 2/5, and blue is 3/5. And blue has 24 more than red.
That means 24 = 1/5
So in total there are 120 small marbles (24*5)
There are 180 big marbles 
We add these together, 120 + 180 = 300 marbles
180 / 300 = 0.6 = 60%
^ Divide the big marbles by the number of total marbles

60% of the marbles are big marbles

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