In a class of 18 students the teacher wants to form a group of 4 to answer homework questions. how many different possible groups are there?

The average hourly earnings for a construction worker is projected to be $24.50 in 2012. jason wants to join the construction work force after he graduates in 2012. his friend tells him that average hourly earnings for construction workers will rise by 2% from 2009 to 2012. based on the data below, assuming that the projected hourly earnings are correct, is jason’s friend’s statement accurate? construction industry - average hourly earnings, 2000-2009 a. his friend’s statement is accurate. the average hourly earnings will increase by 2%. b. his friend’s statement is not accurate. the percent increase will be more than 2% c. his friend’s statement is not accurate. the percent increase will be less than 2% d. his friend’s statement is not accurate. the average hourly earnings will decrease

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.

If the diagram polygon abcd is a reflection across ef to make polygon a'b'c'd'.