NAT Mathematics MCQs

A 76 average over 5 tests requires 380 total marks.
The first four total 300, so 80 more marks are needed.

The LCM uses prime powers 2³, 3, and 5.
Their product is 8 × 3 × 5 = 120.

The decrease is 65 units.
Since 65/650 × 100 = 10%, the decrease is 10%.

The second number is product divided by the first number.
Thus, 216 ÷ 18 = 12.

The median is the middle value in ordered data.
The third of five values is 9.

The mode is the value occurring most often.
The number 4 appears three times.

Range equals maximum minus minimum.
Thus, 40 - 12 = 28.

Matrix order is written as rows by columns.
Therefore, 3 rows and 4 columns give order 3 × 4.

Matrix addition is performed entry by entry.
Each corresponding pair sums to 5.

For [[a, b], [c, d]], determinant = ad - bc.
Thus, 2 × 4 - 3 × 1 = 5.

An identity matrix has 1s on the main diagonal and 0s elsewhere.
It leaves a compatible matrix unchanged under multiplication.

A square matrix is invertible only when its determinant is nonzero.
A zero determinant means the matrix is singular.