MYTUTOR SUBJECT ANSWERS

431 views

The following sequence reads: 8, 5, 2, -1. What are the 4th and 50th terms of this sequence?

With sequences we should follow the general formula of An + B.

The refers to the position in the sequence i.e. for the 3rd number in the sequence (which is 2 in the above sequence) n=3.

The A refers to the difference between each number in the sequence. In the case of the sequence above, A= -3 (each number is 3 lower than the previous one in the sequence). 

The refers to the difference between a particular number in the sequence compared with the number in the same position if it were the 'expected sequence'. In other words if it were just An. So for the sequence above it would be -3n so plugging in n=1, the first value in the sequence would be -3 x 1 = -3.

However we can see that this isn't the case, the first number is actually 8. 8 is 11 higher than -3 (8 - -3 = 8+3 = 11). So B=11.

Therefore the general formula for this sequence is -3n + 11.

All we now have to do is plug in the values for the poisiton in the sequence into n.

So the 4th term in the sequence is when n = 4:

(-3 x 4) = -12 + 11 = -1

And the 50th term in the sequence is when n = 50:

(-3 x 50) = -150 + 11 = -139

Aneesh S. 13 plus  Maths tutor, GCSE Maths tutor, 11 Plus Maths tutor...

9 months ago

Answered by Aneesh, a 13 Plus Maths tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

245 SUBJECT SPECIALISTS

PremiumWilliam A. A Level Law tutor, GCSE Law tutor, A Level Economics tutor...
£36 /hr

William A.

Degree: Law (Bachelors) - Cambridge alumni University

Subjects offered:Maths, Law+ 3 more

Maths
Law
Economics
Chemistry
.LNAT.

“I recently graduated from the University of Cambridge in Law and completed my A Levels in 2012 with 4 A*s in Maths, Economics, Physics and Chemistry.I am a friendly and approachable person and have previously tutored A Level Econom...”

£24 /hr

Sioned D.

Degree: Law (Bachelors) - University College London University

Subjects offered:Maths, History+ 4 more

Maths
History
English
Biology
.LNAT.
-Personal Statements-

“Hello! I'm a University College London Final year Law Student with a great deal of tutoring experience in English, Maths, Sciences and Entrance Exams. ”

£18 /hr

Isobel R.

Degree: Natural Sciences (Bachelors) - Durham University

Subjects offered:Maths, Further Mathematics + 1 more

Maths
Further Mathematics
Economics

“A friendly and enthusiastic Durham student with a love of maths and economics. I'm looking forward to sharing my passion with other students.”

MyTutor guarantee

About the author

Aneesh S.

Currently unavailable: for new students

Degree: Medicine MBBS BSc (Bachelors) - University College London University

Subjects offered:Maths, Chemistry+ 1 more

Maths
Chemistry
Biology

“Let me introduce myself: I'm Aneesh, a second year medical student who has just completed his second year at University College London. Through my own experience of benefitting from many outstanding teachers, I know firsthand the dif...”

MyTutor guarantee

You may also like...

Posts by Aneesh

A cylindrical beaker has a height of 16 cm and a diameter at its bottom of 10 cm. What is its volume? Give your answer to 2 decimal places.

Arrange the following decimals in order of size: 0.45, 1.09, 0.3, 0.08

Outline the process of protein synthesis in a cell.

The following sequence reads: 8, 5, 2, -1. What are the 4th and 50th terms of this sequence?

Other 13 Plus Maths questions

One bag has 4y+2 counters in it and another has 6y-2 counters in it. The bags have the same number of counters in them. Calculate the value of y.

The following sequence reads: 8, 5, 2, -1. What are the 4th and 50th terms of this sequence?

How far is it from one corner of the room to the other?

Bob draws the largest circle he can on a 20cm piece of paper. He then cuts out the circle and looks as the cuttings that are left. What is the total area of the cuttings to the nearest cm?

View 13 Plus Maths tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok