Percents
Percent is a hundredth part of unit. A record 1% means 0.01. There are three main problems by percents:
Problem 1. |
Find an indicated percent of a given number.
The given number is multiplied by the indicated number of percents; then a product is divided by 100. |
E x a m p l e . | A deposit in a bank has an annual increase 6%. A sum of money in the beginning was equal to $10000. How many dollars will the sum be increased by in the end of the year? |
S o l u t i o n : $10000 · 6 : 100 = $600.
Problem 2. |
Find a number by another given number and its percent value of the
unknown number.
The given number is divided by its percent value; the result is multiplied by 100. |
E x a m p l e . | A salary by January was equal to $15000, that was equal 7.5% of an annual salary. What was the annual salary ? |
S o l u t i o n : $15000 : 7.5 · 100 = $200000 .
Problem 3. |
Find the percent expression of one number by another.
The first number is divided by the second, and a result is multiplied by 100. |
E x a m p l e . | On 2001 a plant have produced 40000 cars; and on 2002 - only 36000 cars. What percent does it constitute relatively to the output of 2001 ? |
S o l u t i o n : 36000 : 40000 · 100 = 90% .