# Percentage

## Working with percentages - parts of a whole

Percentage can be calculated as

*p = 100% P / W (1) *

*where *

*p = percentage (%)*

*P = part*

*W = whole*

### Example - Contractors Materials

A contractor spent an amount of *100000* for materials in a custom home project. The total cost of the project was *200000*. The materials percentage cost can be calculated as

*p = 100% (100000) / (200000)*

* = 50%*

### Example - Weight of Engine

Weight of an engine is *200 kg*. The total weight of the car is *1500 kg*. The percentage weight of the engine can be calculated as

*p = 100% (200 kg) / (1500 kg)*

* = 13.3%*

### Example - Increasing Price

The cost of a contract increase from *100000* to *120000*. The percentage increase of the contract price can be calculated as

*p = 100% (120000 - 100000) / (100000)*

* = 20%*

### Example - Decreasing Price

The cost of a contract decrease from *100000* to *80000*. The percentage decrease of the contract price can be calculated as

*p = 100% (100000 - 80000) / (100000)*

* = 20%*