A circular running track is 1/4 mile long. Elena runs on this track, completing each lap in 1/20 of an hour. What is Elena's running speed?

Alicia puts $400 in a bank account. each year the account earns 5% simple interest. how much money will be in her bank account in six months?

Abag contains 4 red, 7 blue and 5 yellow marbles. event a is defined as drawing a yellow marble on the first draw and event b is defined as drawing a blue marble on the second draw. if two marbles are drawn from the bag, one after the other and not replaced, what is p(b|a) expressed in simplest form? a. 7/16 b. 7/15 c. 14/16 d. 14/15

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?