Percentages · Topic 1 of 6

🧮 Percentage Basics

2 exam question types, fully solved

A percent just means “out of 100”. The fastest way to work with one is to swap it for its fraction and divide.

The fraction–percent table to memorise

= 50% · = 33⅓% · = 25% · = 20% · = 16⅔% · = 12.5% · = 10%

• Percent of a number: 12.5% of 800 = = 100 (never multiply by 0.125).

• What % is A of B: write , simplify, read off the percent.

• Find the whole: if 45% = 270, then 1% = 6, so 100% = 600.

• Swap rule: x% of y = y% of x — flip a hard sum into an easy one (e.g. 16% of 25 = 25% of 16 = 4).

🧮Percentage CalculatorBoth directions

find

% of

40% = 2/5→250 × 2/5 =100

(slow way: 250×40/100 = 100 — same answer, more work)

what % is

30 is 20% of 150

25% of 80 = = .

Q1What is 20% of 250?

Q260 is what percent of 240?

Q330% of a number is 90. The number is:

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Real exam questions — Percentage Basics

2 question types · 6 solved examples from real SSC papers

Percent means "out of 100". Turn percents into fractions and most of these become one quick division.

How to solve this type

To take a percent of a number, turn the percent into its fraction and multiply — so memorise the common pairs:

\dfrac{1}{2}=50\%

\dfrac{1}{4}=25\%

\dfrac{1}{5}=20\%

\dfrac{1}{8}=12.5\%

\dfrac{1}{3}=33.33\%

\dfrac{1}{6}=16.67\%

. To remove a

\%

sign divide by 100; to add one, multiply by 100. Use the swap rule x

\%

of y = y

\%

of x to flip hard sums into easy ones. To find the whole from a part, drop to 1

\%

first, then scale up to 100

\%

What is 12.5% of 800?

A80B110C90D100

What percent is 45 of 360?

A12%B10%C12.5%D8%

45% of what number equals 270?

A500B650C600D550