Get an answer in 5 minutes

We'll notify as soon as your question has been answered.

Plus iconAsk a question to our educators
MATHS
Asked by Jodie

There are 3 rectangles A B and C. The area of rectangle B is 10% greater then the area of rectangle A. The area of rectangle C is 10% greater then the area of rectangle B. By what percentage is the area of rectangle C greater then rectangle A?

I have written a full algebraic solution to see this, but there is also a quick way of thinking this through at the bottom. Let's take the area of rectangle A and let us call it - a. Similarly we will call area of rectangle B - b and the same for rectangle C - c. In the question we know area b is 10% bigger then area a. So we can write. <Eq 1> b = 1.1a (or we could write 100a = 110b if we want to work with the percentages - these are equivalent) <Eq 2> Similarly we know: c = 1.1b (or 100c = 110b) Let's rearrange this so we can substitute into <Eq 1> For this we want b by itself on a side. Therefore let's divide both sides by 1.1. c / 1.1 = b Now let's substitute b in to <Eq 1> to allow us to relate a and c. c / 1.1 = 1.1a Multiply both sides by 1.1 c = (1.1 x 1.1)a c = 1.21a To use percentages let's multiply 1.21 So 100% of c - the full area of c is equal to 121% of shape a. The area has increased by 21%. Instead of writing the full algebraic solution, you could think of it as shape a increasing by 10% and then this increasing by 10%. In decimal this is a 1.1 squared increase (1.21).

Alexander's profile picture
Verified
Alexander Stronach
·

2.6k students helped

Similar Maths questions

What is Q&A on Scoodle?

At Scoodle we understand that everyone learns in a different way. Some people learn through practice, using essays and notes; others prefer video lessons to watch and learn, some just need help with a specifically hard question, while some learn best 1-on-1 tutoring sessions. At Scoodle we cater for all types of learning styles and needs. From GCSE Maths video lessons to A-level English essays and specialist educators in every subject - we’ve got you covered.

Faces of students on ScoodleFaces of students on ScoodleFaces of students on Scoodle
Scoodle has helped over 131,000 students so far

5 Maths tutors available now

Need help with A-Level Maths?

Getting expert help from a tutor is a great way to improve your Maths grades.

Badge showing the text 'New'Discover learning resources by tutors

Learn Maths with Video Lessons
GCSE Maths - Numbers
1hr 28m · 8 videos
Paja's profile picture
Paja Kruzikova
·

649 students helped

GCSE Maths - Numbers
Quadratic Inequalities
28m · 3 videos
Iqbal's profile picture
Iqbal Lokman
·

1.4k students helped

Quadratic Inequalities
GCSE Maths - Ratios
1hr 32m · 9 videos
Paja's profile picture
Paja Kruzikova
·

649 students helped

GCSE Maths - Ratios
GCSE Maths - Algebra A
56m · 6 videos
Paja's profile picture
Paja Kruzikova
·

649 students helped

GCSE Maths - Algebra A
GCSE Maths - Algebra B
1hr 14m · 7 videos
Paja's profile picture
Paja Kruzikova
·

649 students helped

GCSE Maths - Algebra B
GCSE Maths - Algebra C
1hr 27m · 9 videos
Paja's profile picture
Paja Kruzikova
·

649 students helped

GCSE Maths - Algebra C