In a deck of cards (no jokers), what is the probability of picking a card with a letter on it?

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle

The party planning committee has to determine the number of tables needed for an upcoming event. if a square table can fit 8 people and a round table can fit 6 people, the equation 150 = 8x + 6y represents the number of each type of table needed for 150 people.

Jonathan puts $400 in a bank account. each year the account earns 6% simple interest. how much interest will be earned in 5 years?