What is the value of the expression 1 - 2 + 3 - 4 + 5 - 6 ..... to 100 terms?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. - 50.
Expression: 1 - 2 + 3 - 4 + 5 - 6 + ... to 100 terms
We can group the terms in pairs: (1 - 2) + (3 - 4) + (5 - 6) + ...
Value of each pair = - 1
Number of pair = 100/2 = 50
Value of the expression = 50 × (- 1) = - 50