Step by step
The question
Question: 30 is 150% of what number?
150% of ? = 30
We write it like this: 150% of the number is 30.
30 is a part.
The whole number is what we want.
? = the whole number
Careful!
Many people work out 150% of 30.
But 30 is not the whole.
It is only 150% of it.
Careful: not 150% of 30 ✗
1 Write the percent as a fraction
Percent means out of 100.
So 150% is 150/100.
150% = 150100
150 and 100 can both be divided by 50.
So 150% is 3/2: 3 parts, when 2 parts make the whole.
= 150 ÷ 50100 ÷ 50 = 32
2 Draw the whole
3 Find one part
3 parts make 30.
So one part is 30 divided by 3.
That is 10.
1 part = 30 ÷ 3 = 10
Every part is 10.
4 Find the whole
The whole is 2 parts.
2 times 10 is 20.
2 parts = 2 × 10 = 20
So 30 is 150% of 20.
5 Check
Let's check: is 150% of 20 really 30?
150% is 3/2.
Of means times.
20 divided by 2 is 10.
3 times 10 is 30.
150% of 20 = 32 × 20 = 3 × 10 = 30 (20 ÷ 2 = 10)
We get 30.
So it is right!
Let's look back.
First: write the percent as a fraction.
Then: draw the whole.
Then: find one part.
Then: find the whole.
Last: check.
Answer
2 parts = 2 × 10 = 20