Find the number which is greater (less) than a given number by P percent.
Formula for calculating number B which is greater than A by P percent.
If we have number A and need to find number B, which greater than A by P percent, then
| B = A(1 + | P | ) |
| 100% |
Formula for calculating number B which is less than A by P percent.
If we have number A and need to find number B, which less than A by P percent, then
| B = A(1 - | P | ) |
| 100% |
Derivation of formulas:
A · P 100% -
add this number to A, if we need to find number B, which greater than A by P percent:
A + A · P = A(1 + P ) 100% 100% subtract this number from A, if we need to find number B, which less than A by P percent:
A - A · P = A(1 - P ) 100% 100%
Examples of solving problems: find the number which is greater (less) than a given number by P percent
Example 1.
Find the number which is greater than 40 by 5%.
Solution.
| 40 · (1 + | 5% | ) = 42 |
| 100% |
Answer: the number 42 is greater than 40 by 5%.
Example 2.
Find the number which is less than 40 by 5%.
Solution.
| 40 · (1 - | 5% | ) = 38 |
| 100% |
Answer: the number 38 is less than 40 by 5%.
Example 3.
What amount will be a year in the bank if you put $ 1,000 on deposit at 10% per annum.
Solution.
| 1000 · (1 + | 10% | ) = 1100 |
| 100% |
Answer: on the deposit will be $ 1,100.
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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