A radio station runs a promotion at an auto show with a money box with 15 $100 tickets, 13 $50 tickets, and 12 $25 tickets. The box contains an additional 20 "dummy”tickets with no value. Three tickets are randomly drawn. Find the probability that all three tickets have no value.

:24% of students in a class are girls. if there are less than 30 students in this class, how many students are there? how many girls are there?

Campus rentals rents 2 and 3 bedrooms apartments for $700 ans $900 a month respectively. last month they had six vacant apartments and reported $4600 in lost rent. how many of each type of apartment were vacant?

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?