A bag contains 20 balls of which x are black, 2x are white and 8 are red. A ball is selected at random from the bag.
What is the probability that it is not black? Give your answer as a decimal.

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7x+8y=-18, 4x-9y=-3 solve the system of equations

Suppose sat writing scores are normally distributed with a mean of 497 and a standard deviation of 109. a university plans to award scholarships to students whose scores are in the top 2%. what is the minimum score required for the scholarship? round your answer to the nearest whole number, if necessary.

Which is greater, 7 p 5 or 7 c 5? 7p5 7c5