Suppose that the value of a stock varies each day from $15 to $24 with a uniform distribution. - Find the upper quartile; 25% of all days the stock

Suppose that the value of a stock varies each day from $15 to $24 with a uniform distribution.

- Find the upper quartile; 25% of all days the stock is above what value?

-Given that the stock is greater than $16, find the probability that the stock is more than $20.