43
Q:

# Three solid cubes of sides 1 cm, 6 cm and 8 cm are melted to form a new cube. Find the surface area of the cube so formed

 A) 486 B) 586 C) 686 D) 786

Explanation:

Volume of new cube =  $13+63+83cm3$$729cm3$

Edge of new cube = $7293$ = 9cm

Surface area of the new cube = ( 6 x 9 x 9) sq.cm = 486 sq.cm

Q:

Find the total surface area (in sq.cm) of a right circular cylinder of diameter 21 cm and height 10 cm.

 A) 1353 B) 1287 C) 1678 D) 1728

Explanation:

5 6130
Q:

Find the area and circumference of a circle if the radius is 14 cm. (Take pi = 22/7)

 A) Area = 44 sq.cm; circumference = 308 cm B) Area = 616 sq.cm; circumference = 88 cm C) Area = 88 sq.cm; circumference = 616 cm D) Area = 308 sq.cm; circumference = 44 cm

Answer & Explanation Answer: B) Area = 616 sq.cm; circumference = 88 cm

Explanation:

1 7536
Q:

Find the curved surface area (in cm2) of a right circular cylinder of diameter 21 cm and height 10 cm.

 A) 594 B) 530 C) 472 D) 660

Explanation:

1 5854
Q:

The length, breadth and height of a cuboidal box are in the ratio 7 : 5 : 3 and its whole surface area is 27832 sq.cm. Its volume is:

 A) 288120 cub.cm B) 280120 cub.cm C) 208120 cub.cm D) 288100 cub.cm

Explanation:

1 740
Q:

Find the total surface area (in cm2) of a right circular cone of diameter 28 cm and slant height 12 cm.

 A) 1714 B) 1161 C) 1144 D) 1477

Explanation:

2 601
Q:

If the edge of a cube is increased by 4 cm, the volume will increase by 988 . Then the original length of each edge of the cube is

 A) 7 cm B) 6 cm C) 9 cm D) 8 cm

Explanation:

3 804
Q:

Find the height of a cuboid whose volume is 330 $cm2$and base area is 15$cm2$ .

 A) 21 cm B) 24 cm C) 22 cm D) 19 cm

Explanation:

2 8468
Q:

Find the volume () of a cuboid of length, breadth and height of 7.5 cm, 5 cm and 6 cm respectively.

 A) 195 B) 180 C) 225 D) 173