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Our online tools will provide quick answers to your calculation and conversion needs. On this page, you can do various calculations involving math percentage problems and get answers to common questions like "**What percent of A is B?**", "**What is A percent of B?**", and "**A is B percent of what amount?**"

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1. What is 40% of 600?

Ans. Since 40% = ^{40}/_{100},

Therefore, 40% of 600 = ^{40}/_{100} × 600 = .4 × 600 = 240

2. What percent is 40 of 800?

Ans. Since we have to find the percentage, we rewrite the problem as:**x**% of 800 = 40

⇒ ^{x}/_{100} × 800 = 40

⇒ **x** × 800 = 40 × 100

⇒ **x** = ^{40 × 100} / _{800}

⇒ **x** = 5%

3. 12 is 20% of what amount?

Ans. Rewriting the problem, we have:

20% × **x** = 12

⇒ ^{20}/_{100} × **x** = 12

⇒20 × **x** = 12 × 100

⇒**x** = ^{12 × 100}/_{20}

⇒**x** = 60

In mathematics, a percentage is a number or ratio expressed as a fraction of 100. i.e., 5% = 5/100 = .05. So a **x**% of a number **y** is **x**/100***y**.

Read more on our tutorial on how to work out percentages.

- Discount
- Fraction
- Ratio
- GCD
- LCM
- Mean, Median, Mode
- Standard deviation
- Number rounding
- Round to nearest multiple
- Speed
- Area
- Volume

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