Question

2
Worksheet 5
1.
Two cubes each of side 6 cm are joined together. Name the new solid formed
and, also find its volume.
2.
Find the height of a cuboid whose volume is 275 cm and base area is 25 cm2.
3.
The dimensions of a box are 60 cm x 54 cm x 30 cm. How many small cubes of side
6 cm can be placed in the box?
If each edge of a cube is doubled,
(i) how many times will its surface area increase?
(ii) how many times will its volume increase?
5.
A match box measures 4 cm x 2.5 cm x 1.5 cm. What will be the volume of a packet
containing 12 such boxes?
6.
Volume of a cube is 1,000 cm3. Find its total surface area.
7.
How many planks each of which is 2 m long, 2.5 cm broad and 4 cm thick can be
cut off from a wooden block 6 m long, 15 cm broad and 40 cm thick?
8.
Three solid metal cubes with edges 6 cm, 8 cm and 10 cm respectively are melted
together and formed into a single cube. Find the volume of new cube.
9.
Find the volume of a cube whose surface area is 150 m2.
10. Find the volume of a cube, one face of which has an area of 81 m².​

Answer 1

Step-by-step explanation:

1. cuboid

volume = 12×6×6= 144 cm³

2. Height= volume ÷ base area

height = 275÷25=11cm

3. No. of cubes= volume of box÷ volume of 1 cube

= (60×54×30) ÷ 6×6×6

450 cubes

(i)if each edge of cube is doubled then the surface area will be 2 times

(ii) The volume will increase 2 times.

5. volume of 1 match box = 4cm × 2.5cm× 1.5cm

= 15cm³

volume of packet containing 12 boxes = 12×15= 180cm³

6.volume of a cube = a³

a³= 1000cm³

a= 10cm

total surface area = 6a² = 6×10×10= 600cm²

7. Do like question no 3 find volume of both and then divide and make the unit of all same.

8.volume of new cube = sum of volume of 3 cubes

= (6cm)³ + (8cm)³+(10cm)³

216cm³+512cm³+1000cm³

1728cm³

9.

10.Area of one face= 81cm²

edge= 9cm

volume = (9cm³)

729cm³