true

Take Class 12 Tuition from the Best Tutors

Affordable fees
1-1 or Group class
Flexible Timings
Verified Tutors

Search in

Algebra (JEE - Main )

Sujoy Das

10/02/2018 0 0

Question:

A sequence of numbers is written in the following fashion: 1, 7, 1, 1, 7, 7, 1, 1, 1, 7, 7, 7, ... till ‘n’ terms. The sum of first 5001 terms of the given sequence is,

a) 5001 b) 20478 c) 19911 d) 39822

Answer:

n(n+1) = 5000, n = 70,

total = 1/2(70*71 + 7*70*71) + 31.

70 terms of 7 and of 1 plus 31 more terms

35*71*(7+1) =19880 + 31

= 19911

Sum has to be odd so A or C

But obviously sum > 5001

Hence C.

0 Like 0 Dislike

Follow 2

Other Lessons for You

Calculus

Following are the formulas used for differentiation(d/dx) (x^n) = nx^(n-1)(d/dx) (e^x) = e^x(d/dx) (logx) = 1/x(d/dx) (sinx) = cosx(d/dx) (cosx) = -sinx(d/dx) (tanx) = sec^2 x(d/dx) (cotx) = -cosec^2x(d/dx)...

Cyber

0 0

Accountancy Basics

Assets - Dr balance Liability- Cr Balance Expence-Dr Balance Income- Cr Balance To Increase Debit Balance Account- Dr To Decrease Debit Balance Account- Cr To Increase Credit Balance Account- Cr To Decrease credit Balance Account- Dr

Akhil Mathew

1 0

IUPAC Nomenclature Chemistry Class - XI

IUPAC nomenclature of organic chemistry : The IUPAC nomenclature of organic chemistry is a systematic method of naming organic chemical compounds as recommended by the International Union of Pure and...

Sudhansu Bhushan Roy

1 0

Superposition Principle Of Forces: Physics

Here I am going to explain superposition principle of forces with an heuristic approach. Let us do a simple experiment. See the above image. Suppose an object of heavy mass is pulled up by a person...

Muthumanimaran

0 0

Chapter -1 Partnership Firms Basics.

CHAPTER 1 Accounting for Partnership Firms Fundamentals According to Section4 of the Indian Partnership Act, 1932: "Partnership is the relationship between persons who have agreed to the share the profits...

Mahesh Kumar

0 0

Find Class XII Tuition near you

Online Tuition Class 12

Looking for Class 12 Tuition ?

Learn from Best Tutors on UrbanPro.

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you

Class 12 Tuition Questions

If a substance contracts on freezing the increase of pressure __________ the freezing point. (Increases, Decreases, Does not Change)

6 Answers

What is the IUPAC Name of salicylic acid ?

27 Answers

When an electron in hydrogen atom jumps from higher orbit into second orbit. The set of lines emitted...

8 Answers

For the Science Student I am asking this Question for Answer : What science ? Give the Answer........

32 Answers

Why are Bryophytes regarded as the amphibians of plant kingdom?

8 Answers

Looking for Class 12 Tuition Classes?

The best tutors for Class 12 Tuition Classes are on UrbanPro

Select the best Tutor
Book & Attend a Free Demo
Pay and start Learning

Take Class 12 Tuition with the Best Tutors

The best Tutors for Class 12 Tuition Classes are on UrbanPro

I am a Student I am a Tutor
Name*	Please enter your full name. Please enter institute name.
Email*	Please enter your email address.
Phone*	Please enter a valid phone number.
Location*	Please enter a pincode or area name.
City*	Please enter city name.
Category*	Please enter category.
Gender*	Male Female Please select your gender.
Email ID/ Mobile No.*	Please enter either mobile no. or email.
Enter Password*	Please enter OTP Please enter Password Sorry, this phone number is not verified, Please login with your email Id.