Percentages & Percentage Change

Dr. Davinder Bhachu & Nick Featherstone

Teachers

Introduction - Percentages & Percentage Change

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Explainer Video

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Worked Examples

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Worked Examples Video

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Dr. Davinder Bhachu

Assistant Head of Chemistry

Nick Featherstone

Assistant Head of Maths

Introduction - Percentages & Percentage Change

What are percentages?

A way of expressing numbers as part of 100.

Example

Cent .

Therefore ‘per-centages’ means out of .

means out of

No answer provided.

How do we calculate percentage change?

Percentage Change =

Example

A jacket originally costs .

It is now .

What is the percentage change in price?

Percentage Change =

Example

New Value =

Old Value =

Percentage Change =

No answer provided.

Why are percentages and percentage change tested in the UCAT?

Assesses your ability to interpret data quickly and draw conclusions from it.

Helps you to identify data trends and to perform calculations quickly based on the information given.

Explainer Video

Filmed by our Maths department, this video walks through currency and unit conversions from first principles.

Worked Examples

Question 1 - Easy

The table below shows the number of players participating in five popular online games across different platforms on a given day.

Gaming Analytics

Game	Total Player Base	Players by Platform	Platform Ratings (100%)
		PC	Mobile
Game 1	10,500	756	399
Game 2	9,400	611	423
Game 3	13,500	567	594
Game 4	2,500	160	80
Game 5	1,875	90	150

Platform rating =

Roughly of the players who accessed Game 2 through the Console were female.

What is the platform rating for Mobile users of Game 3?

Answer

Worked Solution

Platform rating =

Question 2 - Medium

The table shows the total cost of renting different types of photography lighting kits for a certain number of hours. The total cost is calculated using the deposit and the cost per hour. Some information is missing in the table.

Photography Equipment Rental

Kit Type	Hours	Deposit	Cost per Hour	Total Cost
Kit A	2	-	£25	£135
Kit B	4	-	£60	£330
Kit C	8	£100	£75	-
Kit D	10	£95	£100	£1,095

If the deposit for Kit D is increased by on weekends, what is the total cost of renting Kit D for 6 hours on a Sunday?

Answer

Worked Solution

New deposit
Hourly cost
Total cost

Question 3 - Hard

The chart below shows the results of a trial assessing the accuracy of two fraud detection systems (referred to as 'System A' and 'System B') used by a bank to flag fraudulent transactions.

Fraud Detection Accuracy