Q 01/05

Which symbol did Welshman Robert Recorde invent in 1557 to avoid 'the tedious repetition' of a three-word phrase?

A) Equals sign

B) Minus sign

C) Division sign

D) Percent sign

Answer · why

A) Equals sign

The equals sign replaced the words 'is equal to', which Recorde was tired of writing out, and he chose two lines 'because no two things can be more eq...

Q 02/05

Which number name was coined, mathematician Edward Kasner said, by his nine-year-old nephew?

A) Lakh

B) Googol

C) Crore

D) Myriad

Answer · why

B) Googol

Googol, a 1 followed by a hundred zeros, was the boy's suggestion, and a respelling of it later gave the search engine Google its name.

Q 03/05

What is 7 times 8?

A) 15

B) 56

C) 112

D) 560

Answer · why

B) 56

56: a classroom trick is to count 5, 6, 7, 8, because the digits of the answer and the two numbers multiplied line up as 56 = 7 × 8.

Q 04/05

How many squares does a standard chessboard have, laid out as eight rows of eight with the colours alternating?

A) 8

B) 64

C) 128

D) 640

Answer · why

B) 64

64: in a famous legend a grain of wheat is doubled on every square, and the heap that results comes to more than 18 quintillion grains.

Q 05/05

What shape is a standard red stop sign?

A) Pentagon

B) Octagon

C) Decagon

D) Dodecagon

Answer · why

B) Octagon

Octagon: the shape was settled in the 1920s but the colour was not, and American stop signs stayed yellow until the 1950s.