# Find P percent of A

## Formula for calculating P percent of number A.

B | = | A · P |

100% |

For the derivation of this equation using the method of solving problems with percentage

"All" | = | 100% | => | "Part" = | "All" · "Part in %" |

"Part" | "Part in %" | 100% |

## Examples of solving problems: percent from given number

Example 1.

What is 5% of 40.
**Solution:**

5% · 40 | = 2 |

100% |

**Answer:** 5% of 40 is 2.

Example 2.

In a class is 30 students 10% of them is girls. How many girls in the class?
**Solution.**

The number of girls = | 30 · 10% | = 3 |

100% |

**Answer:** in class is 3 girls.

Example 3.

Dad put a deposit 400,000$ at 12% per annum. How much profit will receive a family in a year?
**Solution.**

profit = | 400 000 · 12% | = 48 000 |

100% |

**Answer:** profit is 48,000$.

Percent
Percent Definition. Main information
Decimal to Percent. Percent to Decimal
The method of solving problems with percentage

The most common types of problems with percent:
Find P percent of A
B is P percent of what?
B is what percent of A?
Find the number which is greater (less) than a given number by P percent
Find the number A if known number B which greater (less) than A by P percent

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