# Practical Problem 3

**Electricity and Magnetism**Level 2

**Problem statement:**

You decided to GO-Green in your house and have 3000 credits to spend on an adequate renewable system. Monthly (31 days) you pay 1275 credits on household power consumption and you would love to reduce this by 30%. By looking at the following options and your current credits, choose the most appropriate products and **conclude your answer by the actual percentage of monthly saving**

**Assume the following**

- One light uses 0.1 kWh
- One geyser (100 liters) uses 2.0 kWh
- One geyser (250 liters) uses 3.5 kWh
- One pump uses 1.0 kWh
- Price per kWh is 0.2016 credits

**In your house you have**

- 10 Lights
- 1 geyser (100 liters)
- 1 geyser (250 liters)
- 2 pumps
- Total power consumption of 8.5 kWh

**The Options you have are below**

- Replace all lights for 650 credits, system uses 0.4 kWh
- Replace a 100 liter geyser for 1150 credits, uses 0.8 kWh per geyser
- Replace a 250 liter geyser for 2350 credits, uses 1.3 kWh per geyser
- Variable speed drive for a single pump at 800 credits, uses 0.4 kWh per pump

**Choose the best options to fit your budget of 3000 credits and calculate your actual percentage savings. **

**Your answer seems reasonable.**Find out if you're right!

**That seems reasonable.**Find out if you're right!

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