Arithmetical Reasoning Questions

The reciprocal of a negative number is always a negative number. So that the number and its reciprocal multiply to 1. 

All real numbers except 0 have reciprocals.

Yes, a square is a rhombus. But a rhombus is not a square unless the interior angles are at right angles.

We know that, a square is a quadrilateral with all sides equal and all the interior angles are 90 deg i.e, at right angles. 

Whereas

a rhombus is also a quadrilateral with all sides equal but the interior angles are not at right angles. Hence, if the interior angles of a rhombus are all at right angles (90 deg), then it is square.

Complementary angles are those whose sum is 90.

Given here, is a right angled triangle, where anfle C is 90 deg. In this, sum of Angles A + C = 90, since, sum of angles in a right angled triangle = 180, angle C = 90 and

hence sum of A + B = 180 - C = 180 - 90 = 90.

Hence, the pair of cimplementary angles in the given triangle = Angle A + B.

The product of a number and its reciprocal is always equals to 1.

For Example : Let the number be 4.

Now, its reciprocal is 1/4

Hence, required product = 4 x 1/4 = 1.

Now, take the number as -15.

Then its reciprocal is -1/15

Required product = -15 x -1/15 = 1.

Hence, the product of a number and its reciprocal is 1.

From the given list of numbers, by observing

Only 3 pairs of numbers have the difference of 12.

They are 

20 - 32

44 - 32

44 - 56.