UrbanPro

Take Class 12 Tuition from the Best Tutors

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

The sum of first four terms of an A.P. is 56 . The sum of last four terms is 112. If its first term is 11 then find the number of terms ?

Asked by Last Modified  

Follow 0
Answer

Please enter your answer

Tutor

Let the first term be 'a' Given:- a=11. Also, it is given that sum of its 1st four terms is 56, which means a + a + d + a + 2d + a + 3d=56 => 4a+6d = 56=> 44+6d = 56 Therefore, d=2 Again given that sum of last four terms is 112. a + (n-1) d + a + (n-2)d +...
read more
Let the first term be 'a' Given:- a=11. Also, it is given that sum of its 1st four terms is 56, which means a + a + d + a + 2d + a + 3d=56 => 4a+6d = 56=> 44+6d = 56 Therefore, d=2 Again given that sum of last four terms is 112. a + (n-1) d + a + (n-2)d + a + (n-3)d + a + (n-4)d = 112 putting a=11 and d=2 => 44+8n-20 = 112 So, solving this we get n=11. There are 11 terms in this A.P The series is 11,13,15,17,19,21,23,25,27,29,31. 11+13+15+17=56 31+29+27+25=112 read less
Comments

Tutor

The proof to the Rational Numbers question posted, is as follows:- A number 'n' can be partitioned without repetition in 'n-1' ways. So total number of partitions till 'n-1' let us call this j = 1/2 * (n-2) (n-1)...since there are n-2 partitions for 'n-1' Let this 'n'= p+q As the 1st term of 'n'...
read more
The proof to the Rational Numbers question posted, is as follows:- A number 'n' can be partitioned without repetition in 'n-1' ways. So total number of partitions till 'n-1' let us call this j = 1/2 * (n-2) (n-1)...since there are n-2 partitions for 'n-1' Let this 'n'= p+q As the 1st term of 'n' stars with q=1 p/q will be represented by (j+q)th term. read less
Comments

Tutor

The proof to the Rational Numbers question posted, is as follows:- A number 'n' can be partitioned without repetition in 'n-1' ways. So total number of partitions till 'n-1' let us call this j = 1/2 * (n-2) (n-1)...since there are n-2 partitions for 'n-1' Let this 'n'= p+q As the 1st term of 'n'...
read more
The proof to the Rational Numbers question posted, is as follows:- A number 'n' can be partitioned without repetition in 'n-1' ways. So total number of partitions till 'n-1' let us call this j = 1/2 * (n-2) (n-1)...since there are n-2 partitions for 'n-1' Let this 'n'= p+q As the 1st term of 'n' starts with q=1 p/q will be represented by (j+q)th term. read less
Comments

Trainer

Let the AP be a + (a +d)+ (a+2d)+ (a +3d) +....... .................... + a +(n-1)d + a +(n -2)d + a +(n-3)d +a +(n-4)d a + (a +d)+ (a+2d)+ (a +3d) = 56 4d + 6d = 56 since a = 11, d = 2 sum of the last 4 terms = 112 (n-1)d + a +(n -2)d + a +(n-3)d +a +(n-4)d =112 4a + (4n-10)d = 112 plug...
read more
Let the AP be a + (a +d)+ (a+2d)+ (a +3d) +....... .................... + a +(n-1)d + a +(n -2)d + a +(n-3)d +a +(n-4)d a + (a +d)+ (a+2d)+ (a +3d) = 56 4d + 6d = 56 since a = 11, d = 2 sum of the last 4 terms = 112 (n-1)d + a +(n -2)d + a +(n-3)d +a +(n-4)d =112 4a + (4n-10)d = 112 plug in a = 11 and d= 2 that gives us n = 11 terms read less
Comments

Tutor - Maths and computer science

Let the A.P. be a, a + d, a + 2d, a + 3d, ... a + (n -- 2) d, a + (n -- 1)d. Sum of first four terms = a + (a + d) + (a + 2d) + (a + 3d) = 4a + 6d Sum of last four terms = + + + = 4a + (4n -- 10) d According to the given condition, 4a + 6d = 56 ? 4(11) + 6d = 56 ? 6d = 12 ? d = 2 ? 4a +...
read more
Let the A.P. be a, a + d, a + 2d, a + 3d, ... a + (n – 2) d, a + (n – 1)d. Sum of first four terms = a + (a + d) + (a + 2d) + (a + 3d) = 4a + 6d Sum of last four terms = [a + (n – 4) d] + [a + (n – 3) d] + [a + (n – 2) d] + [a + n – 1) d] = 4a + (4n – 10) d According to the given condition, 4a + 6d = 56 ? 4(11) + 6d = 56 [Since a = 11 (given)] ? 6d = 12 ? d = 2 ? 4a + (4n –10) d = 112 ? 4(11) + (4n – 10)2 = 112 ? (4n – 10)2 = 68 ? 4n – 10 = 34 ? 4n = 44 ? n = 11 Thus, the number of terms of the A.P. is 11. read less
Comments

Hardworking

11 terms
Comments

Maths Teacher

First term is 11.Sum of first 4 terms is 4a+6d=56. That is 44+6d=56.So d=2 Sum of last four terms is 4a+d=4a+(4n-10)d=112 (4n-10)2= 112-44=68. 4n-10=34. 4n=44 Hence n=11
Comments

Teaching is my passion!!!!

use formula..and put in equation ..(tn =a +(n-1)d, sn =(n/2)(a+l)...
Comments

Qualified and Experienced Tutor

number of terms 11
Comments

Math Educator for Std.11th ,12th , Engineering Entrance and Degree Level with 11+ Years Experience

number of terms = 11
Comments

View 16 more Answers

Related Questions

Find the probability that a non leap year has 53 sundays..
A non leap year has 365 days. There are 52 weeks each having 7 days. This amounts to 52 x 7 = 364 days. The remaining 1 day can be any day among Monday, Tuesday,..., Sunday. Hence the required probability is 1/7.
Kumar Upendra Akshay
Elaborate the steps involved in on-line trading.
(1) Registration (2)placing an order (3)payment mechanism(4)digital cash
Jitender
0 0
6
What are the differences between a primary cell and a secondary cell?
Primary cells are batteries that are not easily recharged after use, while secondary cells are those which can be recharged.
Anmol
1 0
6

Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com

Ask a Question

Related Lessons

Integration of sin x from first principles
y' = Lt /∆x ∆x => 0 Therefore if y = sin x y' = Lt / ∆x ∆x=>0 y' = Lt /∆x ∆x => 0 =>Lt /∆x ∆x => 0 => Lt / ∆x ∆x => 0s =>sin x Lt(cos...
P

Pramod .

1 0
0

Maths- ur best friend.
Its understanding of urs about the maths that matters a lot. There are some learning tips which helps you a lot. 1. Be relaxed and dont take too much tension. 2. Try to learn concept first and then...

Introduction To Accounting: Part 19: Verifiable Objective Concept
The Verifiable Objective Concept holds that accounting should be free from personal bias. Measurements that are based on verifiable evidences are regarded as objectives. It means all accounting...

Question from Biology (Immunology)
What would you have to do in order for you to develop artificially-acquired active immunity? Immune system is bodies’ integral defense mechanism which works to keep the body at a steady state. Immunity...
S

Subimal Banerjee

0 0
0

TOPIC ...(Genetics ) Class X -BIOLOGY
DNA as genetic material-DNA (Deoxyribo nucleic acid )and RNA (Ribonucleic acid )are two major types of nucleic acid found in cells .Chemical composition of nucleic acids ....Sugar ;phosphate group;and...

Recommended Articles

Radhe Shyam is a highly skilled accounts and finance trainer with 8 years of experience in teaching. Accounting is challenging for many students and that’s where Radhe Shyam’s expertise comes into play. He helps his students not only in understanding the subject but also advises them on how to overcome the fear of accounts...

Read full article >

Mohammad Wazid is a certified professional tutor for class 11 students. He has 6 years of teaching experience which he couples with an energetic attitude and a vision of making any subject easy for the students. Over the years he has developed skills with a capability of understanding the requirements of the students. This...

Read full article >

Raghunandan is a passionate teacher with a decade of teaching experience. Being a skilled trainer with extensive knowledge, he provides high-quality BTech, Class 10 and Class 12 tuition classes. His methods of teaching with real-time examples makes difficult topics simple to understand. He explains every concept in-detail...

Read full article >

Urmila is a passionate teacher with over 8 years of experience in teaching. She is currently pursuing her Ph. D. She provides classes for Class 11, Class 12, MBBS and Medical tuition.  Urmila began her career in teaching long before she became a teacher. She used to provide classes for foreign national students in her college...

Read full article >

Looking for Class 12 Tuition ?

Learn from the Best Tutors on UrbanPro

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you
X

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

This website uses cookies

We use cookies to improve user experience. Choose what cookies you allow us to use. You can read more about our Cookie Policy in our Privacy Policy

Accept All
Decline All

UrbanPro.com is India's largest network of most trusted tutors and institutes. Over 55 lakh students rely on UrbanPro.com, to fulfill their learning requirements across 1,000+ categories. Using UrbanPro.com, parents, and students can compare multiple Tutors and Institutes and choose the one that best suits their requirements. More than 7.5 lakh verified Tutors and Institutes are helping millions of students every day and growing their tutoring business on UrbanPro.com. Whether you are looking for a tutor to learn mathematics, a German language trainer to brush up your German language skills or an institute to upgrade your IT skills, we have got the best selection of Tutors and Training Institutes for you. Read more