Test yourself with sequences and series- Practise for JEE MAIN from previous AIEEE papers
Take it like an exam
Following are five number of questions on SEQUENCES AND SERIES and you are supposed to attempt these questions in 10 minutes. You may rate your score as indicated below to understand how your preparation for JEE MAIN or JEE ADVANCED is going on:
A. If you score 5 out of 5, your preparation is going on in an excellent way. Do not look back, just move on with this speed.
B. If you score is 4 out of 5 your preparation is going on in a good way. You need to slightly fine tune your methods and maintain the pace to enter the 5 out of 5 .
C. If you score 3 out of 5 your preparation, though, is OK, you need to buck up your spirits and surge ahead to do the necessary catch-up.
D. 2 or below 2 is a matter of concern. Don’t lose heart. Get into the act more intensely.
The sum of an arithmetico-geometric series is found as below
Apply common sense
Sometimes MCQ type tests provide us scope to guess the answer just by applying common sense. In this problem too we can reach the answer by first considering n=1 and finding the sum. By inspection the sum should be 1. So option (a) is eliminated. For n=3, sum should be 18 just by inspection of the series. Obviously correct option is found as (b)