10th Class Mental Ability Cube and Dice Cubes and Dice

This chapter leads us with problems on various situations of blocks like as:

1.     Number of blocks in a solid.

2.     Construction of a box/dice.

3.     Identification of a face of a dice.

Types of Questions

Ø  To count the total number of blocks in a solid, add the number of blocks in the first (bottom layer, second layer, third layer and so on.

Ø  To identify a box formed by folding a given sheet of paper or by its net, focus on the opposite faces of the box.

Ø  To identify a face of a particular dice whose different positions are shown, select the common faces and then analyse to find their adjacent and opposite faces.

Let us illustrate you by taking examples with explanations.

EXAMPLE

1.         The sheet of paper shown in Fig. (X) is to be folded to form a box.

             Choose from the boxes P, Q, R and S that are similar to the box so formed.

(a) Q and R only                         (b) P, R and S only  

(c) Q and S only                         (d) P and S only

Explanation (b):

When a cube is formed by folding the sheet shown, the face corner opposite to one of two shaded faces.

Also, two white faces lie opposite to each other.

All the above conditions are carried by figures P, R and S.

So, the correct option is (b).

 2.         A dice is thrown two times and its two different positions are given below.

             Find the number on the face opposite to the face showing 3.

(a) 2                                          (b) 4              

(c) 5                                          (d) 6

Explanation (d):

1, 2, 5, 4 are on the adjacent faces of 3.

So, 6 is on the opposite face of 3.

\[\therefore \] The answer is (d).