Me understand this discrete math concept.
how does p(x< = a) + p(x > a) = 1 becomes [p(x < = a) > = 1 - e[x]/a ?

On saturday a souvenir shop had 125 customers.sixty four percent of the costumers paid with a credit card. how many costumers paid with cash?

Which of the following contains a variable?

In trapezoid abcd, ac is a diagonal and ∠abc≅∠acd. find ac if the lengths of the bases bc and ad are 12m and 27m respectively.