Calculate: `1-2+3-4+5-6+7-8+...+49-50.`

Calculate : 1-2+3-4+5-6+7-8+-...+19-20

Find 7-5+4+3-2-6-8 .

Evaluate: -3/8 + 5/8 + 7/8 , (ii) 11/3 + -5/3 + -2/3 , (iii) -1+ 2/(-3) + 5/6 , (iv) 7/26 + (-11)/13 + 2 , (v) 3+(-7/8) + -3/4 , (vi) -13/8 + 7/16 + (-3)/4

Calculate the following a. (6.7 xx 10^(5)) xx (4.6 xx 10^(4)) b. (7.6 xx 10^(7)) xx (3.8 xx 10^(-4)) c. (6.8 xx 10^(-3)) xx (5.2 xx 10^(-4)) d. (6.7 xx 10^(5)) / (4.6 xx 10^(4)) e. (7.6 xx 10^(7)) / (3.8 xx 10^(-4)) f. (6.8 xx 10^(-3)) / (3.8 xx 10^(-4)) g. 7.65 xx 10^(2) + 2.72 xx 10^(3) h. 7.87 xx 10^(-4) - 2.61 xx 10^(-5)

Construct a frequency distribution table for the following data, taking class-intervals 4-6, 6-8 , ............. 14-16 . 11.5, 6.3, 7.8, 9.2, 10.5, 4.5, 6, 8.3, 12.5, 15.8, 7.4, 5.3, 8.4, 15.2, 8.9, 9.8, 8.25, 6.5, 5.8, 10.5, 14.2, 15.3, 11.7, 9.9, 8.8, 6.6, 4.3, 4.7, 9.4, 10.1, 15.5, 14.4, 12.2, 7.7, 5.5 .

Let U = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} and A = {1, 3, 5, 7, 9} . Find A^(prime) .

Find the minor of element 6 in the determinant Delta=|1 2 3 4 5 6 7 8 9|

Find the matrix X so that X[[1, 2, 3],[ 4 ,5, 6]] = [[-7,-8,-9],[2,4,6]]

Find the matrix X so that X[[1, 2, 3],[ 4 ,5, 6]] = [[-7,-8,-9],[2,4,6]]

Which is greaster : 2/7 of 3/4 or 3/5 of 5/8 (ii) 1/2 of 6/7 or 2/3 of 3/7