Monday, September 7, 2026
These are the 10 questions BrainRank served to the whole world on Monday, September 7, 2026 — now over, with every answer revealed and explained. Reading time only; the score no longer counts.
-
arts
How many colors are commonly identified in a rainbow spectrum?
- 5
- 6
- 7
- 9
Answer: 7
A rainbow is traditionally described as having seven colors.
-
math
What is 13 × 4?
- 48
- 54
- 52
- 56
Answer: 52
13 × 4 = 52.
-
science
The formula CO2 represents which common gas?
- Carbon monoxide
- Methane
- Oxygen
- Carbon dioxide
Answer: Carbon dioxide
CO2 is one carbon atom bonded to two oxygen atoms: carbon dioxide.
-
everyday-science
What is the boiling-hot molten rock beneath the Earth's surface called?
- Lava
- Magma
- Sediment
- Basalt
Answer: Magma
Molten rock below the surface is called magma; once it erupts it is called lava.
-
nature
How many legs does a spider have?
- Two
- Four
- Six
- Eight
Answer: Eight
Spiders are arachnids with four pairs of legs, eight total.
-
history
Which ancient civilization developed the concept of a republic that influenced later governments?
- Rome
- Egypt
- Persia
- Babylon
Answer: Rome
The Roman Republic pioneered republican government that influenced many later states.
-
arts
What is the complementary color of red on a standard artist's color wheel?
- Blue
- Green
- Orange
- Yellow
Answer: Green
On a traditional color wheel, green sits opposite red and is its complement.
-
geography
The Andes mountain range runs along which continent?
- North America
- Africa
- Asia
- South America
Answer: South America
The Andes run along the western edge of South America.
-
everyday-science
Which nutrient found in bread, rice, and pasta is the body's main source of energy?
- Proteins
- Vitamins
- Carbohydrates
- Minerals
Answer: Carbohydrates
Carbohydrates are the body's primary energy source.
-
geography
The Alps mountain range is located primarily on which continent?
- Asia
- Europe
- North America
- Africa
Answer: Europe
The Alps stretch across south-central Europe.