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

Calculate : 1-2+3-4+5-6+7-8+9-10

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

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

The additive inverse of S, where S =1 - 2 + 3 -4 + 5 -6 + 7 - 8 + ...+ 49 - 50 is

The additive inverse of S, where S = 1 - 2 + 3 - 4 + 5 - 6 + 7 - 8 + …. + 49 - 50 is

What should come next in the following series? 1 2 3 4 5 6 7 8 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 7 6 5 4 3 2 1 1 2 3

In a mathematics test following marks were obtained by 40 students.Arrange these marks in a table using tally marks. 8 1 3 7 6 5 5 4 4 2 4 9 5 3 7 1 6 5 2 7 7 3 8 4 2 8 3 5 8 6 7 4 5 6 9 6 4 4 6 6 Find how many students obtained marks equal to or more than 7?

If U= {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, A= {1, 2, 3, 5}, B= {2, 4, 6, 7} and C= {2, 3, 4, 8}. Then, (B cup C)'="………"

If U= {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, A= {1, 2, 3, 5}, B= {2, 4, 6, 7} and C= {2, 3, 4, 8}. Then, (C - A)'="……….."