Whats the answer of twice a number b

Chosen according to the volume of oil it can haul, as shown in at a railway yard, locomotives are used to haul containers carrying the table. locomotive capacity a450 0 -750 cubic feet cg35 750-1,500 cubic feet br73 1,500-2,500 cubic feet yh61 2,500-3,500 cubic feet & the four cylindrical containers listed in the table need to be hauled. cylinder length (ft.) diameter (ft.) fill level a 40 , 12 half b 24 8 full c 16 16 full 6 12 full d match each container to the locomotive needed to haulit a450 cylinder a yh61 cylinder d

In the year 2005, the enrollment at lincoln community college (lcc) was 3100 students.in 2007, the enrollment was 3350 students.if lcc's enrollment continues to increase at the same rate, hiw many students will be enrolled at lcc in 2013?

Maximize the lateral surface area of an inverted cone if v=27. formulas: v=pi*r^2*h/3 surface area=pi * r* sqrt of (r^2+h^2) i found that h=81/pi*r^2, but i don't know where to go after this.