Q 01/05

Which background colour did American stop signs carry from 1924 to 1954, before the switch that drivers know today?

A) Yellow

B) White

C) Purple

D) Blue

Answer · why

A) Yellow

Yellow stop signs with a red or black legend ruled American roads for thirty years because fade-resistant red materials were not available. The red oc...

Q 02/05

The Moscow–Washington hotline, made a priority by the 1962 Cuban Missile Crisis, first ran on which equipment?

A) Satellite phones

B) Teleprinters

C) Red telephones

D) Shortwave radios

Answer · why

B) Teleprinters

Teleprinters carried the first hotline messages, and no red phones were ever used: the famous 'red telephone' is a popular-culture invention. Fax mach...

Q 03/05

Which colour did M&M's add in 1976 to replace red, pulled over a scare about a dye the sweets never used?

A) Blue

B) Tan

C) Orange

D) Purple

Answer · why

C) Orange

Orange joined the mix in 1976 because the public was wary of any red-dyed food after Red Dyes No. 2 and No. 4 were judged carcinogenic, even though M&...

Q 04/05

Britain's 1865 'Red Flag Act' made a walker, usually a boy, go how far ahead of every steam road vehicle?

A) 60 yards

B) 100 yards

C) 200 yards

D) 440 yards

Answer · why

A) 60 yards

60 yards ahead, carrying a red flag, was the Locomotives Act's warning system, and the same Act capped road locomotives at 4 mph in the country and 2 ...

Q 05/05

Why is a matador's muleta traditionally dyed a colour that bulls, being dichromatic, cannot actually make out?

A) To hide bloodstains

B) To provoke the bull

C) To honour Spain's flag

D) To stand out for judges

Answer · why

A) To hide bloodstains

To hide bloodstains, and for tradition, is why the muleta stays red even though bulls are dichromatic and cannot discern the colour of the cape or the...