Question 60

The sum of 3rd and 15th elements of an arithmetic progression is equal to the sum of 6th, 11th and 13th elements of the same progression. Then which element of the series should necessarily be equal to zero?

Solution

The sum of the 3rd and 15th terms is a+2d+a+14d = 2a+16d
The sum of the 6th, 11th and 13th terms is a+5d+a+10d+a+12d = 3a+27d
Since the two are equal, 2a+16d = 3a+27d => a+11d = 0
So, the 12th term is 0

Create a FREE account and get:

All Quant CAT complete Formulas and shortcuts PDF
35+ CAT previous papers with video solutions PDF
5000+ Topic-wise Previous year CAT Solved Questions for Free

CAT Quant Questions | CAT Quantitative Ability

CAT Number Systems Questions CAT Remainders Questions CAT Progressions and Series Questions CAT Profit And Loss Questions CAT Arithmetic Questions

CAT DILR Questions | LRDI Questions For CAT

CAT Data change over a period Questions CAT Charts Questions CAT Games and Tournamnents Questions CAT DI with connected data sets Questions CAT Truth Lie Concept Questions

CAT Verbal Ability Questions | VARC Questions For CAT

CAT Reading Comprehension Questions CAT Verbal Ability Questions CAT Miscellaneous Questions CAT Para Jumbles Questions CAT Para Summary Questions

CAT 2003 QA (Leaked) Question

The sum of 3rd and 15th elements of an arithmetic progression is equal to the sum of 6th, 11th and 13th elements of the same progression. Then which element of the series should necessarily be equal to zero?

CAT Quant Questions | CAT Quantitative Ability

CAT DILR Questions | LRDI Questions For CAT

CAT Verbal Ability Questions | VARC Questions For CAT

Free Quant Questions

Login to your Cracku account

Hello! 👋

Ready to Unlock Your Success?

Please Enter Your OTP

Please enter the following details

Create a free Cracku account