The committee responsible for making the arrangements for an upcoming conference can rent the following sizes of tables. There are 600 people registered for the conference. All of the following combinations of tables will allow all those registered to be seated. Which will allow them to be seated at the LEAST cost?

A community is concerned about the high volume of commuter traffic in front of its elementary school between 8:30 A.M. and 9:00 A.M. The numbers of cars that passed without dropping off a student during that half hour on consecutive school days are: 65, 72, 83, 96, 53, 76, 54, 70, 75, 48, 56. What is the mean (average) of these numbers of cars?  

Biologists tagged trout and released them into a new man-made lake. The numbers of trout by gender and species are shown in the table below.

Later, biologists will net and inspect 50 of the tagged fish and re-release them into the lake. If the netting captures fish randomly and all of the fish remain in the lake, approximately how many of the 50 fish are likely to be speckled trout?   

A real estate agent has an appointment to show a house to a couple who lives out of town. It will take the couple 2½ hours to drive to the house, but the real estate agent can get there in 45 minutes. If the couple left at 15 P.M., at what time should the real estate agent leave to arrive at the house at the same time?

When a solar flare occurs on the Sun, it can send out a blast wave that travels through space at a speed of 1.875 × 106 miles per hour. How would this speed, in miles per hour, be written as a decimal number?