IMO Practice Test — The Wonderful World of Science
6 Questions • 15 min • Olympiad level
15:00
Question 1 of 6
Two plants are kept in identical pots, soil, water and sunlight; only one is given plant food. This setup is designed mainly to:
Make a fair test by changing only one variable
Save space on a windowsill
Use less water
Grow flowers quickly
Explanation: Keeping everything the same except the plant food makes it a fair test.
Question 2 of 6
A student measures a rod three times and gets 20.1 cm, 20.0 cm and 20.2 cm. Repeating the measurement mainly helps to:
Make the rod longer
Reduce mistakes and check the result is reliable
Change the unit
Prove the ruler is broken
Explanation: Repeating measurements and getting close values shows the result is reliable.
Question 3 of 6
Which pair is correctly matched as observation → inference?
The grass is wet → it rained last night
It rained → the grass is green
The dog is brown → the dog is brown
It is morning → the time is 7 o’clock
Explanation: Wet grass is observed; rain is inferred from it.
Question 4 of 6
A hypothesis differs from a conclusion because a hypothesis is made:
After the experiment, using the results
Before the experiment, as a testable prediction
Only by famous scientists
Without any question
Explanation: A hypothesis is a prediction made before testing; a conclusion comes after.
Question 5 of 6
Which question is the MOST scientific because it can be measured?
Is winter nicer than summer?
Does salt water boil at a higher temperature than plain water?
Which fruit is tastiest?
Is reading better than drawing?
Explanation: Boiling temperature can be measured and compared; the others are opinions.
Question 6 of 6
Why do scientists communicate their results to others?
To keep their work secret
So others can check, repeat and build on the findings
To avoid doing experiments
Because results are always opinions
Explanation: Sharing allows others to reproduce the work, which makes science reliable.