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Numerical Ability
Co-ordinate geometry
All faces of a cube with an eight-meter edge are painted red. If the cube is cur into smaller cubes with a two-meter edge, how many of the two-meter cubes have paint on exactly one face?
a)24
b)36
c)60
d)48
Read Solution (Total 14)
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- clearly there will be 16 coloumns of 4 cube each formed after cutting the 8m cube into 2m cube.there are 8 cube in layer1,8 cube in layer 2 and 8 cube in layer3 and 4 cube in layer 4 which has one sided painted
so total is 4+8+8+8=24 cubes(ans)
short formula for find one side painted cube is
6(n-2)^2=6[(4-2)]^2=6*4=24 cubes(ans)
here we take n=4,because if we cut 8m cube into 2m cube,then there will 4 cubes produced.
if any query post:) - 12 years agoHelpfull: Yes(69) No(45)
- 1)There will be 16 columns of 4 cube each formed after cutting the 8m cube into 2m cube(Imagine 4 by 4 dimensional cube each of 1 unit length.
2)There will be 4 layers.
3)Consider layer 1:
i)front face of cube,we have 4 cubes.Count=4
ii)Right side face of cube,we have again 4 cubes.But only middle 2 will be counted as end 2 faces are already included in count.Now count=4+2=6
iii)Back side of cube,we have again 4 cubes.Count=4+2+4=10
iv)Now 4th side of cube,again 2 middle cube will be counted,bec 2 end cubes are already counted.Now Count=4+2+4+2=12
v)Consider top side of cube,we have only middle 4 cubes.Now, Count=4+2+4+2+4=16
4)Consider layer 2: Total count=16
5)Consider Layer 3:Total count=16
6)Consider Layer 4:Total count=16
ADD step count(3,4,5,6).
We get total count=16+16+16+16=48
Sol:option d)48 - 12 years agoHelpfull: Yes(28) No(38)
- but according to opensuse test 24 is the wrong answer...plz anyone can help me to find exact answer
- 12 years agoHelpfull: Yes(18) No(11)
- if u draw the dia.. then u can see exactly 4 cubes in each side painted one side ...
so total no. of cubes=4*6=24
and it is the most perfect ans. - 12 years agoHelpfull: Yes(11) No(4)
- 24 is the answer
- 12 years agoHelpfull: Yes(8) No(5)
- rani u are right
- 12 years agoHelpfull: Yes(6) No(5)
- please tell the correct answer 24 0r 48???
- 11 years agoHelpfull: Yes(4) No(1)
- consider the top layer, 4*4=16 cubes we can fill by making 2mt edge so using 16 cubes in one layer, the other layer automatically uses 4 cubes if u observe so we need nly 12 cubes for other layers so totally we need 16+12+12+12+12-16=48.. so the answer is 48
- 11 years agoHelpfull: Yes(2) No(9)
- 24..draw d cube..d 4 cubes of 2 cm in d middle of each face will hv xactly one face painted..so we hv 6 faces ..therefore..6*4=24
- 9 years agoHelpfull: Yes(2) No(1)
- how cum 16 column?
- 11 years agoHelpfull: Yes(1) No(1)
- 60
((4*4)*4)-4=60 - 10 years agoHelpfull: Yes(1) No(1)
- please explain why is it 16 columns of 4 cube and how is the answer 24?
- 9 years agoHelpfull: Yes(1) No(0)
- why parag 4 cubes in last layer. Can u provide diagram
- 9 years agoHelpfull: Yes(0) No(0)
- 4 smaller cubes on each face of the larger cube will have exactly one face painted.
So total number of smaller cubes with exactly one face painted= 4*6=24(a)
- 9 years agoHelpfull: Yes(0) No(0)
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