- Option : A
- Explanation :

Given, BD = 40 cm, AM =16 cm , NC=12cm

∴ Here, BD divides quadrilateral in two triangles.

Now,

Area of ΔABD = 1/2 x BD xAM

1/2 x 40 x 16 =320 cm∧2.

∴ Area of ΔBCD = 1/2 x BD x NC

=1/2 x40 x12=240 cm∧2

Area of quadrilateral

ABCD = 320 + 240 = 560 cm∧2

2. A cuboid is of dimensions 5 cm × 2 cm × 5 cm. How many such cuboids may be joined to form a cube?

- Option : D
- Explanation : (D) Given that, sides of a cuboid are 5cm, 2cm and 5cm.

Volume of cuboid = 5 × 2 × 5 = 50cm^{3}

Let the side of the cube formed with minimum number of cuboids = x

Hence, volume of the cube = x^{3}

Let, number of cuboids required = n

Hence, n × 50 = x^{3}

n × 50 must be perfect cube i.e.

minimum value of n = 2 × 2 × 5 = 20

Volume of the cube formed = 20 × 50 = 1000 cm^{3}

So, required cuboids = 20

- Option : C
- Explanation : Given, lb = x.

bh=y,lb=z.

lb x bh x lh = xyz.

l^{2}b^{2}b^{2}=xyz

Volume = lbh = √xyz

- Option : A
- Explanation : Here h =r

∴ Required ratio

=πr^{2}h: (2/3)πr^{3}: (1/3) πr^{2}h

=1:2/3:1/3 =3:2:1

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