Reasoning
ISBT Reasoning for all banking PO,Clerk,IBPS PO,Railway,SSC,IAS,OAS Exams
Q1. 

1)  127  2)  178 
3)  218  4)  279 
5)  None of these 
Answer : 218
Explanation : The number of cubes whose at least one face is painted = One face painted + two face painted + three face painted = One face visible + two face visible + three face visible = Total  (No face visible) = 343  125 = 218
Explanation : The number of cubes whose at least one face is painted = One face painted + two face painted + three face painted = One face visible + two face visible + three face visible = Total  (No face visible) = 343  125 = 218
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Q2. 

1)  27  2)  64 
3)  125  4)  216 
5)  None of these 
Answer : 125
Explanation : The number of cubes where no face is painted = The number of cubes who one face is visible
Explanation : The number of cubes where no face is painted = The number of cubes who one face is visible
= (a  2)^{3} = (7  2)^{3 }= 125.
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Q3.  Direction : A cube is painted red and all its faces and is then divided into 343 equal cubes.How many cubes will have one face painted ? 
1)  112  2)  148 
3)  150  4)  162 
5)  None of these 
Answer : 150
Explanation : The number of cubes whose one face is painted = The number of cubes who one face is visible = 6 (a  2)^{2} = 6 (7  2)^{2} = 150
Explanation : The number of cubes whose one face is painted = The number of cubes who one face is visible = 6 (a  2)^{2} = 6 (7  2)^{2} = 150
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Q4. 

1)  45  2)  50 
3)  56  4)  60 
5)  None of these 
Answer : 60
Explanation :
Explanation :
Since, the cube is divided into 343 equal cubes i.e. (7)3 equal cubes, assume the edge length of the cube to be 7, (a = 7). This is done using the idea of unit cubes. (A cube of edge length a unit can be divided into a^{3} unit cubes)
The number of cubes whose two faces are painted = The number of cubes whose two faces are visible = 12 (a  2) = 12 (7  2) = 60
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Q5. 

1)  0  2)  4 
3)  8  4)  16 
5)  None of these 
Answer : 8
Explanation :
Explanation :
Since the cube is divided into 343 equal cubes i.e. (7)3 equal cubes, assume the edge length of the cube to be 7, (a = 7). This is done using the idea of unit cubes. (A cube of edge length a unit can be divided into a^{3} unit cubes)
The number of cubes whose three face are painted is equal to the number of cubes whose three faces are visible. (Since only those faces which are visible can be painted).
Hence, the number is 8.
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Q6. 
Directions : Study the following information and answer the questions given below. 
1)  4  2)  8 
3)  16  4)  20 
5)  None of these 
Answer : 16
Explanation :
Explanation :
Number of cubes with black and green colours are 8. Remaining cubes = 24  8 = 16
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Q7. 

1)  4  2)  8 
3)  12  4)  24 
5)  None of these 
Answer : 24
Explanation : Total number of cubes = 6 x 4 = 24
Explanation : Total number of cubes = 6 x 4 = 24
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Q8. 
Directions : Study the following information and answer the questions given below. 
1)  2  2)  4 
3)  8  4)  12 
5)  None of these 
Answer : 4
Explanation :
Explanation :
Questions on rectangular block are to be proceeded in the same way as the questions on cube. But one important pointlength, breadth and height are different in rectangular block.
Cubes with three colours will obviously be lying at the corner of the given rectangular block. Since there are lour corners so the number of such cubes will be 4.
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Q9. 

1)  1  2)  2 
3)  4  4)  D.I 
5)  None 
Answer : 1
Explanation : The cube of this category will be one in number and located in the centre of the cube.
Explanation : The cube of this category will be one in number and located in the centre of the cube.
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Q10. 

1)  4  2)  6 
3)  8  4)  12 
5)  None of these 
Answer : 6
Explanation : The cubes of category (ii) with one face painted will be those lying in the centre of each face and this will be six in number.
Explanation : The cubes of category (ii) with one face painted will be those lying in the centre of each face and this will be six in number.
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