PPT: Ratios, Proportions & Scales

 Page 1


Ratios and Proportions 
for UCAT
Solve ratio and proportion questions fast4
use fractions, benchmark values and 
elimination to simplify and score more 
marks.
Page 2


Ratios and Proportions 
for UCAT
Solve ratio and proportion questions fast4
use fractions, benchmark values and 
elimination to simplify and score more 
marks.
Two-Part and Three-Part Ratios
Two-Part Ratios
Most common 
format. Numerator 
left of colon, 
denominator right. 
Can be written as 4:3 
or 4/3.
Three-Part Ratios
Separated by two 
colons (e.g., 1:2:5). 
Cannot be directly 
written as fraction, 
but work with two 
parts at a time.
Word Format
Ratios described with 'to' replacing colon. 
Sometimes 'for' used in full sentences.
Page 3


Ratios and Proportions 
for UCAT
Solve ratio and proportion questions fast4
use fractions, benchmark values and 
elimination to simplify and score more 
marks.
Two-Part and Three-Part Ratios
Two-Part Ratios
Most common 
format. Numerator 
left of colon, 
denominator right. 
Can be written as 4:3 
or 4/3.
Three-Part Ratios
Separated by two 
colons (e.g., 1:2:5). 
Cannot be directly 
written as fraction, 
but work with two 
parts at a time.
Word Format
Ratios described with 'to' replacing colon. 
Sometimes 'for' used in full sentences.
Forming Ratios Correctly
Key Steps
Pick correct values from data
Assign numerator and 
denominator accurately
Watch for common factor to 
reduce
Divide using calculator if needed
Common Pitfall
Take care not to reverse or invert the 
sides of the ratio when converting 
from colon format to fraction.
Page 4


Ratios and Proportions 
for UCAT
Solve ratio and proportion questions fast4
use fractions, benchmark values and 
elimination to simplify and score more 
marks.
Two-Part and Three-Part Ratios
Two-Part Ratios
Most common 
format. Numerator 
left of colon, 
denominator right. 
Can be written as 4:3 
or 4/3.
Three-Part Ratios
Separated by two 
colons (e.g., 1:2:5). 
Cannot be directly 
written as fraction, 
but work with two 
parts at a time.
Word Format
Ratios described with 'to' replacing colon. 
Sometimes 'for' used in full sentences.
Forming Ratios Correctly
Key Steps
Pick correct values from data
Assign numerator and 
denominator accurately
Watch for common factor to 
reduce
Divide using calculator if needed
Common Pitfall
Take care not to reverse or invert the 
sides of the ratio when converting 
from colon format to fraction.
Reducing Ratios Efficiently
01
Spot Common Factors
Look for simple factors 
like 2, 3, 5, or composite 
factors like 6, 8, 10, 25.
02
Reduce Before Dividing
Simplify both sides to 
make calculations easier, 
especially if one side 
reduces to 1.
03
Use Calculator as Backup
Divide out the ratio and compare decimal values to 
answer choices.
Page 5


Ratios and Proportions 
for UCAT
Solve ratio and proportion questions fast4
use fractions, benchmark values and 
elimination to simplify and score more 
marks.
Two-Part and Three-Part Ratios
Two-Part Ratios
Most common 
format. Numerator 
left of colon, 
denominator right. 
Can be written as 4:3 
or 4/3.
Three-Part Ratios
Separated by two 
colons (e.g., 1:2:5). 
Cannot be directly 
written as fraction, 
but work with two 
parts at a time.
Word Format
Ratios described with 'to' replacing colon. 
Sometimes 'for' used in full sentences.
Forming Ratios Correctly
Key Steps
Pick correct values from data
Assign numerator and 
denominator accurately
Watch for common factor to 
reduce
Divide using calculator if needed
Common Pitfall
Take care not to reverse or invert the 
sides of the ratio when converting 
from colon format to fraction.
Reducing Ratios Efficiently
01
Spot Common Factors
Look for simple factors 
like 2, 3, 5, or composite 
factors like 6, 8, 10, 25.
02
Reduce Before Dividing
Simplify both sides to 
make calculations easier, 
especially if one side 
reduces to 1.
03
Use Calculator as Backup
Divide out the ratio and compare decimal values to 
answer choices.
Benchmark Comparison to 1
1
Greater Than 1
Numerator larger than 
denominator. Eliminate answers 
between 0 and 1.
2
Between 0 and 1
Numerator smaller than 
denominator. Eliminate answers 
greater than 1.
Use this eyeball comparison to quickly eliminate wrong answers and save 
time.