11FM - One quantity as % of another

11FM - One quantity as % of another

One quantity as a percentage of another

We often change quantities into percentages to make it easier to compare them.

For example we change our test results to a percentage to make it easier to understand how we performed across many assessments that have different numbers of questions.

Example 1

Multiple Select

Practice 1: There are 320 year 10 students and 180 of them are boys. Write the number of boys in year 10 as a fraction of the total number of students. (Select the whole fraction AND the fraction in simplest form - 2 answers)

• 9/16

• 5/10

• 1/2

• 180/320

Multiple Choice

Practice 2: Find 30% of $500

• $100

• $150

• $30

• $280

Multiple Choice

Practice 3: Sophie achieved a score of 14/20 on a maths test. What is her result as a percentage?

• 14%

• 50%

• 70%

• 90%

Multiple Choice

Write 5 hours as a percentage of a day. (Hint: How many hours are there in one day?

• 20%

• 20.8%

• 2.8%

• 20%

Multiple Choice

Write 7cm as a percentage of 40cm

• 0.175%

• 1.75%

• 17.5%

• 21%

Multiple Choice

Which pink blocks represent 65%?

• A
• B
• C 
• D

Fill in the Blank

Jasman finished  $\frac{3}{5}$  of his homework. What percentage o his homework did he finish?

Fill in the Blank

A jogging route is 10km long. Zaman has jogged 4km. What percentage of the route has Zaman jogged?

Multiple Choice

Write 300g as a percentage of 2kg. (Hint: How many grams are in 1 kilogram?)

• 5%

• 15%

• 55%

• 80%

Multiple Choice

In her driving test, Melanie answered 21 out of 24 questions correct. The pass mark on the driving test is 95%. Did Melanie pass?

• Yes

• No

• No idea

Fill in the Blank

Joe earns $670 per week and pays $210 in tax. What percentage of his weekly wage does he pay in tax? (Give answer to 1 decimal place)

Multiple Choice

Express 5 minutes as a percentage of 2 hours

• 40%

• 18%

• 4%

• 1%

Multiple Choice

Express 75c as a percentage of $6

• 12.5%

• 10%

• 26%

• 75%

End of Lesson!

If you need some more practice try some other questions from ch 2.4 of your textbook :)