Everyone loves quizzes, right? Right. So, in honour of our 15^{th} anniversary here at LuminUltra, here are 15 questions that’ll let you test just how much you know about water.

**1. What’s the average pH level of fresh water?**

a) 3

b) 5

c) 7

d) 9

**2. What percentage of the Earth’s water supply is fresh water?**

a) 1

b) 3

c) 10

d) 20

**3. How is most of the Earth’s fresh water held?**

a) Underground aquifers

d) Lakes

d) Man-made reservoirs

**4. What property of water allows water molecules to stick together?**

a) Adhesion

b) Coagulation

c) Evaporation

d) Cohesion

**5. Approximately what percentage of water used by people worldwide goes towards agriculture?**

a) 20

b) 70

c) 90

d) 10

**6. After climbing Mount Everest, you decide to have a cup of tea. In degrees Celsius, at what temperature can you expect your water to boil?**

a) 96

b) 70

c) 82

d) 100

**7. What is the longest river on Earth?**

a) Amazon

d) Mississippi

c) Yangtze

d) Congo

**8. ****Worldwide, how many plastic water bottles are purchased every minute?**

a) 100,000

b) 10,000

c) 500,000

d) 1,000,000

**9. What percentage of the Earth’s surface is covered by water?**

a) 45

b) 70

c) 55

d) 60

**10. Approximately what percentage of the human body is water?**

a) 62

b) 90

c) 76

d) 34

**11. What was the name of the Ancient Greek god of water?**

a) Apollo

b) Artemis

c) Poseidon

d) Hera

**12. Where is the deepest point in the Earth’s oceans located?**

a) Tonga Trench

b) South Sandwich Trench

c) Puerto Rico Trench

d) Mariana Trench

**13. Approximately how many litres of water must a dairy cow drink to produce one litre of milk?**

a) 12

b) 4

c) 8

d) 2

**14. There is variation between species but, on average, how many litres of water does a mature tree give off each day through evaporation?**

a) 80

b) 250

c) 400

d) 950

**15. What’s the deepest lake in the world?**

a) Lake Superior (Canada/USA)

b) Lake Toba (Indonesia)

c) Lake Baikal (Russia)

d) Lake Hauroko (New Zealand)

**Answers:**

1. C, 2. B, 3. A, 4. D, 5. B, 6. B, 7. A, 8. D, 9. B, 10. A, 11. C, 12. D, 13. B, 14. B, 15. C