AREA MCQS SET-7

1. The perimeter of one face of a cube is 20 cm. Its volume will be:
A) 125cm3125cm3125cm3
B) 400cm3400cm3400cm3
C) 250cm3250cm3250cm3
D) 625cm3625cm3625cm3
Ans. A
Edge of cude = 20/4 = 5 cm

Volume = a*a*a = 5*5*5 = 125 cm cube View Answer

2. The cost of the paint is Rs. 36.50 per kg. If 1 kg of paint covers 16 square feet, how much will it cost to paint outside of a cube having 8 feet each side.
A) Rs. 850
B) Rs. 860
C) Rs. 876
D) Rs. 886
Ans. C
Surface area =6a2=6*82=384sq feetQuantity required =38416=24kgCost of painting =36.50*24=Rs.876Surface area =6a2=6*82=384sq feetQuantity required =38416=24kgCost of painting =36.50*24=Rs.876Surface area =6a2=6*82=384sq feetQuantity required =38416=24kgCost of painting =36.50*24=Rs.876

3. How many cubes of 10 cm edge can be put in a cubical box of 1 m edge.
A) 10000 cubes
B) 1000 cubes
C) 100 cubes
D) 50 cubes
Ans. B
Number of cubes =100*100*10010*10*10=1000Number of cubes =100*100*10010*10*10=1000Number of cubes =100*100*10010*10*10=1000

Note: 1 m = 100 cm

4. If the volume of two cubes are in the ratio 27:1, the ratio of their edges is:
A) 3:1
B) 3:2
C) 3:5
D) 3:7
Ans.A
Let the edges be a and b of two cubes, then

a3b3=271=>(ab)3=(31)3ab=31=>a:b=3:1a3b3=271=>(ab)()3=(31)3ab=31=>a:b=3:1a3b3=271=>(ab)()3=(31)3ab=31=>a:b=3:1

5. A circular well with a diameter of 2 meters, is dug to a depth of 14 meters. What is the volume of the earth dug out.
A) 40m340m340m3
B) 42m342m342m3
C) 44m344m344m3
D) 46m346m346m3
Ans. C
Volume=pr2hVolume=(227*1*1*14)m3=44m3Volume=pr2hVolume=(227*1*1*14)m3=44m3Volume=pr2hVolume=(227*1*1*14)m3=44m3