Question

in a group of 400 ,each of whom atleast accountant or management or sales manager .it was found that 160 are only accountant ,220 are only management and 260 sales manager . 50 are accountant as well as sales manager , and 20 are accountant as well as managemet as well as sales manager. find the number of those who are accountant as well as managemet but not sales manager
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Answer 1

Answer:

We're asked to check whether a square pyramid, satisfying the following properties, really exists or not.

Since the square pyramid is made using a square of side 16 cm,

Length of base edge, \sf{a=16\ cm}a=16 cm

The triangle used to make has one side of length 16 cm, which should be attached to side of the square, so that the other sides of the triangle, measuring 10 cm each, should be slant edge of the square pyramid.

Length of slant edge, \sf{e=10\ cm}e=10 cm

Let's find the height of the square pyramid, \sf{h,}h, which is given by,

$\longrightarrow\sf{h=\sqrt{e^2-[(\dfrac{a}{2})^2+(\dfrac{a}{2})^2]}}$⟶h=

$\longrightarrow\sf{h=\sqrt{e^2-[\dfrac{a^2}{4}+\dfrac{a^2}{4}]}}$⟶h=

$\longrightarrow\sf{h=\sqrt{e^2-\dfrac{2a^2}{4}}}$⟶h=

$\longrightarrow\sf{h=\sqrt{e^2-\dfrac{a^2}{2}}}$⟶h=

Putting values of \sf{e}e and \sf{a,}a,

$\longrightarrow\sf{h=\sqrt{10^2-\dfrac{16^2}{2}}}$⟶h=

$\longrightarrow\sf{h=\sqrt{100-\dfrac{256}{2}}}$⟶h=

$\longrightarrow\sf{h=\sqrt{100-128}}$⟶h=

$\longrightarrow\sf{h=\sqrt{-28}\ cm}$⟶h=

Well, square root of a negative number is not real. This implies the square pyramid does not exist.

Hence, we can't make a square pyramid using square of side 16cm, and four triangles each with one side 16 cm and the other two sides of 10 cm each.