can you guys help in this questing (question is in this link, )they force to pay for help.
http://www.chegg.com/homework-help/questions-and-answers/suppose-new-office-building-planned-architect-wants-design-building-thick-base-eventually--q1399042

So it basically sum of volume of 10 trapezoid prism.
So,
area of a floor y = area of the ceiling of the floor x, where y=x+1

So, basically we can find the vloume of 10 different trapezoid prism and sum them up.

V= (1/2)*(Area of the floor  + area of its celing) * (height of the room)
V=(15/2)*(Area of the floor+Area of the celing) [Notice that height of the room is the same for each floor=15 units)
Total Volume= sum of all Vs.
for instance,
V1= (25+23)* (15) cubic units
    =360 unit^3.

So your total volume should be 2190 cubic units.

Thanks much, is there anyway we can solve this problem via intragal method?

The volume of each floor is calculated as 

Where l represents the lenght of the floor, w is for the width and h is the height.
You have the area of each floor, and also the height.

The area of the floor is caculated as 

So if you use this equation in the first I gave to you, one can obtain this:

The volume for each floor is then calculated with the data you gave in the problem.

For example, for the first floor you have Area=25 ft. and Height=15 ft.

The volume of the first floor is then V=A*h=(25 ft.)*(15 ft.)=375 square feet

Calculating for the rest of the floors:

Floor number	Area (ft.)	Height (ft.)	Volume (sq ft.)
Ground	25	15	375
2	23	15	345
3	20	15	300
4	18	15	270
5	16	15	240
6	14	15	210
7	12	15	180
8	10	15	150
9	9	15	135
10	8	15	120
Roof	7	15	105

Then you calculate the total volume of the building, summing the volume column of the table.

The total volume of the building is 2430 square feet.

 

 This could be Reimann sum which is part of calculus 1. Are you taking Calc 3?

this there is no function given nor we have any addition information igven, we need to do reimann sum.
I think taking volume of trapeziod prism will be better than taking cuboids.

yas this is cal II problem?
that will be great if you show me process of Reimann sum.

 hint;
here
delta x= delta height = 15/2
anf f(x) =(1/2) of ( bottom area+ top area)

@geshe BIG thanks for your help. I wanna share my happiness with you that I got 99 on that 'home exam' paper. Thanks.

Wow 99 is a really good grade!!!! Congratulation!!! I am really happy for you