MYTUTOR SUBJECT ANSWERS

274 views

What is the sum of the factors of 21?

To answer this question, we first need to work out the factors of 21. These are the whole numbers which multiply to make 21. 

We know that 1 multiplies with 21 to make 21, so they are both factors. 

2 is not a factor of 21, because we cannot multiply it with another whole number to make 21.

3 is a factor of 21, because it multiplies with 7 to make 21. 

Therefore the factors of 21 are 1, 3, 7 and 21. 

All that is left to do is to work out the sum of these numbers, that is to add them all up. 

21+1 + 3 +7 = 32

Therefore, the sum of the factors of 21 is 32. 

Melissa P. GCSE Maths tutor, 13 plus  Maths tutor, 11 Plus Maths tuto...

4 months ago

Answered by Melissa, a 11 Plus Maths tutor with MyTutor


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

119 SUBJECT SPECIALISTS

£18 /hr

Gabrielle M.

Degree: Mechanical Engineering (Masters) - Birmingham University

Subjects offered: Maths

Maths

“I am a student studying Mechanical Engineering in my first year at University of Birmingham. I enjoy the challenges my course throws at me and I enjoy both the practical and theoretical elements of the course. In the course this year ...”

£18 /hr

Emily L.

Degree: Law (Bachelors) - Durham University

Subjects offered: Maths, English Literature+ 1 more

Maths
English Literature

“I am a first year undergraduate reading Law at Durham University. Prior to this, I attended the Tiffin Girls' School in Kingston upon Thames where I studied English Literature, Chemistry and Fine Art at A2 Level (with additional Mathe...”

£18 /hr

Olivia K.

Degree: Philosophy, Politics and Economics (Bachelors) - Oxford, Magdalen College University

Subjects offered: Maths, Politics+ 3 more

Maths
Politics
Philosophy and Ethics
.TSA. Oxford.
-Oxbridge Preparation-

“About Me: I am a second year student at Oxford studying Philosophy, Politics and Economics. I have a real passion for Politics, specialising in American studies and British government in the last 100 years but I also come from a very ...”

MyTutor guarantee

About the author

£18 /hr

Melissa P.

Degree: Mathematics (Bachelors) - Birmingham University

Subjects offered: Maths, Spanish

Maths
Spanish

“About me:  I am currently studying for a Maths degree at the University of Birmingham. I have enjoyed Maths since I was very young and hope I can pass some of this on to you!  I am very friendly. I have been coaching gymnastics since...”

You may also like...

Posts by Melissa

Factorise fully 3*a^3*b +12*a^2*b^2 + 9*a^5*b^3

Find the 100th term in the sequence 3, 7, 11, 15...

Find the highest common factor of 432 and 522

Find the next three terms of the sequence 17, 14.5, 12, 9.5

Other 11 Plus Maths questions

A group of 120 Year 4s and Year 5s are going on a school trip. 60% of the children going on the trip are Year 4s, and of the Years 4s, 1/4 are boys. How many Year 4 girls are going on the trip?

When a price changes from £15 to £20. By how much percentage has the price changed?

Arrange the following decimals in order of size, from largest to smallest: 0.34, 1.06, 0.3, 0.09

How many 1/3's are there in 9?

View 11 Plus Maths tutors

Cookies:

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

mtw:mercury1:status:ok