Follow this to solve any variation problem systematically.
Ready to give DSE variation exercises a try? Here are some tips to get you started: dse variation exercise
The monthly electricity bill ($C) is partly constant and partly varies directly as the number of units used (u). When 200 units are used, the bill is $300. When 500 units are used, the bill is $600. Find the bill when 800 units are used. Follow this to solve any variation problem systematically