Percentages of quantities questions with answers

Questions

1. Question 1Find a percentage of a number

   Find $75\%$ of $80$.

   Show the worked solution

   1. Step 1: Write the percentage as a fraction out of 100, then multiply$75\% \text{ of } 80 = \dfrac{75}{100} \times 80$$= 60$
2. Question 2A percentage of a quantity in context

   A hawker centre has 40 stalls. 35% of the stalls sell drinks. Find the number of stalls that sell drinks.

   Show the worked solution

   1. Step 1: Write the percentage as a fraction out of 100, then multiply$35\% \text{ of } 40 = \dfrac{35}{100} \times 40$$= 14$$14$ stalls sell drinks.
3. Question 3Express one quantity as a percentage of another

   Express $15$ as a percentage of $16$.

   Show the worked solution

   1. Step 1: Write the first quantity as a fraction of the second, then multiply by 100%$\dfrac{15}{16} \times 100\%$$= 93.75\%$
4. Question 4Change to the same unit first

   Express $500$ m as a percentage of $4$ km.

   Show the worked solution

   1. Step 1: Change both quantities to the same (smaller) unit$4 \text{ km} = 4 \times 1000 \text{ m}$$\phantom{4 \text{ km}} = 4000 \text{ m}$
   2. Step 2: Write the first quantity as a fraction of the second, then multiply by 100%$\dfrac{500}{4000} \times 100\%$$= 12.5\%$
5. Question 5A percentage as a fraction

   Write $15\%$ as a fraction in its simplest form.

   Show the worked solution

   1. Step 1: Per cent means out of 100: divide by 100, then simplify$15\% = \dfrac{15}{100}$$= \dfrac{3}{20}$