76. Determinant of a 3X3 square matrix is called —– determinant
(A) First order
(B) Second order
(C) Third order
(D) Fourth order
Answer:
(C) Third order
Explanation:
The order of a determinant is determined by the number of rows (or columns) in its square matrix. A 3×3 matrix has a 3rd order determinant.
77. Find out the values of ‘x’ and ‘y’ if x + y = 7; 3x – 2y = 11.
(A) 4, 3
(B) 5, 2
(C) 3, 4
(D) 2, 5
Answer:
(B) 5, 2
Explanation:
Multiply the first equation by 2: 2x + 2y = 14. Add this to the second equation (3x – 2y = 11) to get 5x = 25, meaning x = 5. Substituting back gives y = 2.
78. The number of children in 10 families in a locality is listed: 3, 1, 4, 0, 2, 1, 1, 2, 3, 3. Find out the average number of children in a family.
(A) 1
(B) 2
(C) 3
(D) 4
Answer:
(B) 2
Explanation:
Summing the values (3+1+4+0+2+1+1+2+3+3) gives 20. Dividing by the 10 families gives an average of 20 / 10 = 2.
79. Which among the following is a measure of Dispersion?
(A) Mean
(B) Mode
(C) Median
(D) Range
Answer:
(D) Range
Explanation:
Mean, median, and mode are measures of central tendency. Range evaluates the spread of data points, making it a measure of dispersion.
80. Find out the mode of the values 5, 10, 3, 10, 2, 9, 5, 10, 2, 11
(A) 2
(B) 5
(C) 10
(D) 11
Answer:
(C) 10
Explanation:
The mode is the number that appears most frequently in a dataset. 10 appears three times, which is more often than any other number.
