1)In a shower, 5 cm of rain falls. The volume of water that falls on 1.5 hectares of ground is:
a)75 m3
b) 750 m3
c) 7500 m3
d) 75000 m3
Answer:b) 750 m3
Explanation:
1 hectare = 10,000 m2
So, Area = (1.5 x 10000) m2 = 15000 m2.
Depth =
5/100
m =
1/20
m
Volume = (Area x Depth) =(15000 x
1/20
)m3 = 750 m3
2) A boat having a length 3 m and breadth 2 m is floating on a lake. The boat sinks by 1 cm when a man gets on it. The mass of the man is:
a) 12 kg
b) 60 kg
c) 72 kg
d) 96 kg
Answer:b) 60 kg
Explanation:
Volume of water displaced = (3 x 2 x 0.01) m3
= 0.06 m3.
Mass of man = Volume of water displaced x Density of water
= (0.06 x 1000) kg
= 60 kg.
3)The slant height of a right circular cone is 10 m and its height is 8 m. Find the area of its curved surface.
a) 30Πm2
b) 40Πm2
c) 60Πm2
d) 80Πm2
Answer:b) 60Πm2
Explanation:
l = 10 m,
h = 8 m.
So, r = √l2 - h2 = (10)2 - 82 = 6 m.
Curved surface area = Πrl = (Π x 6 x 10) m2 = 60 m2.
4) The perimeter of one face of a cube is 20 cm. Its volume will be:
a) 125cm3
b) 400cm3
c) 250cm3
d) 625cm3
Answer:a) 125cm3
Explanation:
Edge of cude = 20/4 = 5 cm
Volume = a*a*a = 5*5*5 = 125 cm3
5)How many cubes of 10 cm edge can be put in a cubical box of 1 m edge.
