Find the score that separates the top 80% from the bottom 20%. the Mean= 100

Standard deviation = 25

7) Suppose that a class of 20 students is assigned to write an essay. Suppose 4 essays are picked at random. How many groups of 4 are possible? What if the 4 essays picked at random are given awards of $35, $20, $10, and $5. How man}r groups of 4 are possible now