In the sequence of numbers 4,7,-7.., each even term is 3 more than the previous and odd term is -1 times the previous... [CLOSED]

Question

In the sequence of numbers 4,7,-7,....., the first term is 4. Each even numbered term is 3 more than the previous term.Each odd numbered term after the first is -1 times the previous term. What is the sum of the first 22 terms?

Answer 1

Answer is 11.
The series follows like this:
4, 7 , -7, -4, 4, 7, -7, -4, 4, 7, -7, .....
All terms get cancelled other than 4 & 7.
So 4+7=11.

Comments

Thanks...