Volume of a cone with a diameter of 3.5 and a height of 8.4.

volume is 26.9

Step-by-step explanation:

Volume of a cone is calculated by V=πr^2h/3

Where π is a constant, with value of 3.14

h is height, given as 8.4

r is radius, radius = diameter ÷ 2

Since Diameter is given as 3.5, radius = 3.5/2 = 1.75

Slot the values into the formula

V= 3.14 x 1.75^2 × 8.4/3

= 3.14 x 3.06 x 2.8

=26.9

I hope this helps.

120960

Step-by-step explanation:

We get 11 books   7 of geography  and  4  of chemistry

We need to line all of them  with 2 constraints

1.-three of the geography must be: 1 in the middle and in each end, then we already have

C₄,₃   =   4! / ( 4 - 3 ) !     C₄,₃   =  4*3*2*1

C₄,₃   =   24  different ways

Now we have 7 books of chemistry. To place them we get

P₇  = 7!     P₇ =  7*6*5*4*3*2*1         P₇  = 5040

Now the total number will be

C₄,₃* P₇  =  120960