Maths / Arithmetic Progression / Sum of First n Terms

QUESTION
 

If the sum of first n terms of an AP is n(3n + 7) , then its 10th term is ________

OPTIONS
A. 

63

B. 

-64

C. 

64

D. 

16

Right Option : C

EXPLANATION
Explain TypeExplanation Content
Text

large S_n=n(3n+7)

We know,large S_n=S_n_-_1=a_n

So,large S_1_0-S_9=a_1_0=10(3X10+7)-9(3X9+7)

=370-306=64

View Contents
(Concept based Learning and Testing for [6th - 10th], NTSE, Bank & Govt. Exams)
Self Learning
Testimonials
No Preview
PARENT FEEDBACK c/o Manish Kumar C/o ABHYAS Academy
 10th
Abhyas is good institution and a innovative institute also. It is a good platform of beginners.Due to Abhyas,he has got knoweledge about reasoning and confidence.My son has improved his vocabulary because of Abhyas.Teacher have very friendly atmosphere also.
Back
Courses We Offer
(Concept based Learning and Testing for [6th - 10th], NTSE, Bank & Govt. Exams)