Question

Some of the measures of certain cuboids are given below. Use them to complete the table.

S. No	(1)	(2)	(3)	(4)	(5)	(6)
Length	7 cm	15 cm	−	3.5 cm	4.8 m	−
Width	5 cm	10 cm	12 cm	−	3.5 m	1.6 m
Height	3 cm	4 cm	8 cm	2 cm	−	0.5 m
Volume	−	−	1920 cu cm	21 cu cm	42 cu m	2 cu m

Answer 1

(1) Length of the cuboid = 7 cm
Breadth of the cuboid = 5 cm
Height of the cuboid = 3 cm
Volume of the cuboid = length × breadth × height
= 7 × 5 × 3 cm³
= 105 cm³

(2) Length of the cuboid = 15 cm
Breadth of the cuboid = 10 cm
Height of the cuboid = 4 cm
Volume of the cuboid = length × breadth × height
= 15 × 10 × 4 cm³
= 600 cm³

(3) Let the length of the cuboid be l cm.
Breadth of the cuboid = 12 cm
Height of the cuboid = 8 cm
Volume of the cuboid = length × breadth × height
or 1920 = l × 12 × 8
or 1920 = l × 96
or $\frac{1920}{96}=l$ (On dividing both sides by 96)
or 20 cm = l
∴ Length of the cuboid is 20 cm.

(4) Let the breadth of the cuboid be b cm.
Length of the cuboid = 3.5 cm
Height of the cuboid = 2 cm
Volume of the cuboid = length × breadth × height
or 21 = 3.5 × b × 2
or 21 = b × 7
or $\frac{21}{7}=b$ (On dividing both sides by 7)
or 3 cm = b
∴ Breadth of the cuboid is 3 cm.

(5) Let the height of the cuboid be h m.
Length of the cuboid = 4.8 m
Breadth of the cuboid = 3.5 m
Volume of the cuboid = length × breadth × height
or 42 = 4.8 × 3.5 × h
or 2 = 16.8 × h
or $\frac{42}{16.8}=h$ (On dividing both sides by 16.8)
or 2.5 m = h
∴ Height of the cuboid is 2.5 m.

(6) Let the length of the cuboid be l m.
Breadth of the cuboid = 1.6 m
Height of the cuboid = 0.5 m
Volume of the cuboid = length × breadth × height
or 2 = l × 1.6 × 0.5
or 2 = l × 0.8
or $\frac{2}{0.8}=l$ (On dividing both sides by 0.8)
or 2.5 m = l
∴ Length of the cuboid is 2.5 m.

S. No	(1)	(2)	(3)	(4)	(5)	(6)
Length	7 cm	15 cm	20 cm	3.5 cm	4.8 m	2.5 m
Width	5 cm	10 cm	12 cm	3 cm	3.5 m	1.6 m
Height	3 cm	4 cm	8 cm	2 cm	2.5 m	0.5 m
Volume	105 cu cm	600 cu cm	1920 cu cm	21 cu cm	42 cu m	2 cu m