In this section we will try to understand the theory of cubes and dices which is part of the syllabus of verbal reasoning. We have tried our best to draw diagram and illustration for your better understanding but you have to use your imagination to fully grasp the concept.
Concepts of Cubes and Dice
What is Dice
A dice in shape is same as cube or cuboid.
At a time we can see only three views of dice that is front view, top view and side view
There are two types of dice-
1. Standard dice
If sum of opposite face or surface of a dice is equal to 7 then the dice is called standard dice
2.General dice
If the sum of adjacent face or surface of a dice is equal to 7 then the dice is called general dice
Note– A dice can never be both general dice and standard dice
Two opposite numbers or surfaces can never be adjacent to each other
There are four cases through which questions can be asked in exam
1st case
When only one position or view of dice is given
In this type of question we generally check that the dice is standard dice or general dice
Examples-
- When it is standard dice
Here sum of any adjacent side is not equal to 7
So for calculating the opposite side of any digit we simply subtract that digit from 7
That is opposite digit of 2 is =7-2=5
Opposite digit of 6 = 7-6=1
- When it is general dice
Here sum of 4 and 3 is 7
So if we want to find a digit opposite to 4 so it can be either 1 or 6 or 5
We don’t exactly determine which digit should be opposite to 4
2nd case
When only two position or view of dice are given
In this type of question there are three possibilities
1.When there is no common digit between two dice
Examples-
Here there is no common digit
So we find that the dice is standard or general dice
Here the dice is standard dice
So if we find the digit opposite to 6 so it will be 7-6 =1
Opposite to 5 will be 7-5= 2
Opposite to 4 will be 7-4= 3
2.When there is only one common digit between two dice
Example 01
Here 6 is common in both dice
So in this dice if we have to find digit opposite to 3
Then starting from common digit we move clock wise direction and write all digits in sequence
Example 02
Here 3 is common in both dice
So in this dice if we have to find digit opposite to 1
Then starting from common digit we move clock wise direction and write all digits in sequence
Example 03
So here E is opposite to C
3. When there are two common digits between two dice
In this type of questions besides from common digits reaming digits are opposite to each other
Example 01
Here 6 and 2 are common digits in both dice
Note– In above question if we have to find the digits opposite to 6 and 2 that it may be either 4 or 5
Example 02
Note– In above question if we have to find the digits opposite to 6 and 2 that it may be either 4 or 5
3rd case
When more than two position of view of dice are given
Example 01
In first view of cube 6 is adjacent to 3 and 2
And in second view of cube 6 is adjacent to 3 and 5
So clearly here 5 is opposite to 2
And in second view 5 is adjacent to 6, and 3 and 4 and 3 in third view
So from here we say that 4 is opposite to 6
Example 02
In this type of question we choose two such dice which have two common elements
Here we have to choose an alphabet which is opposite to word
So we choose second and third dice for our solution
In both dices E and C are common, so the word opposite to D should be A
4th case
This is the case of opening of a dice
In this case all alternate surface of a dice are opposite to each other
Example 01
This is a unfolded dice and we have to find after folding this where should be position of alphabets
So here alternate alphabets should be opposite to each other
F will be opposite of B
E will be opposite of C and
A will be opposite of D
After folding this our dice is formed as
Example 02
If figure of dices are given in question and we have to find which dice is formed after folding
So for that question we use elimination method
That is
Here C will be opposite of F
B will be opposite of D
A will be opposite of E
Here C will be opposite of F that means F can not be adjacent to C
so here we don’t get C adjacent to F in any dice
B will be opposite of D so eliminate option (c)
And the last A will be opposite of E so eliminate option (a)
So here we get (b) and (d) as our required dice
Cubes and Cuboid
In this section the questions are asked as follows-
1st case
In this type, cube is colored with different colors in which same color is in opposite faces
And we have to find the number of cubes with a combination of different colors
Example-
Here total number of cubes = 43=64
And we have to find those cubes which has only red painted
So here we find middle cubes of level 2 and 3 (in front side and back side) have only red colors shown below as dotted points
So total number of red colored cubes in front side and back side are 4+4=8
So Here there is 8 such cubes
Example 02
Here we have to find how many cubes have two colors
So our figure is-
Here cube is made up of 27 cubes and having 3 different colors
So below dotted points show the cubes which have only two colors
Here in each level we get four such cubes which have two colored surfaces
So total colored surfaces are 4×3=12
So here we get 12 such cubes
2nd case
In this case we have to find total number of cubes in given cuboid
Example-
- Here figure is shown below
So here we have to find total cubes in big cuboid
So we multiply the numbers of column from each view that is
Front view = 6 column
Top view = 2 column
Side view = 2 column
So total number of cubes = 6×6×2 =72
Here we get total 72 cubes