Question

A jar contained 50 marbles. Of the 50 marbles, 90% of them were red and the remainder were green. Some of the red marbles were removed from the jar and after this, 75% of the marbles in the jar were red. How many red marbles were removed from the jar?

Answer 1

so there were 45 reds.
If x were removed, then
(45-x)/(50-x) = 3/4
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