Q 01/05

A $100 jacket is marked up 10%, then put on sale at 10% off; what is the final price?

A) $90

B) $99

C) $101

D) $110

Answer · why

B) $99

$99 is the final price because the 10% discount comes off the larger $110, removing $11 rather than $10. A rise and a fall of the same percentage neve...

Q 02/05

Sound covers roughly 343 metres a second; how far away is lightning whose thunder arrives 3 seconds later?

A) About 100 m

B) About 1 km

C) About 10 km

D) About 100 km

Answer · why

B) About 1 km

About 1 km is right, since 343 × 3 is 1,029 metres. Counting three seconds for every kilometre between the flash and the bang is a standard way to jud...

Q 03/05

Which shape is the cross-section when an upright cylinder, like a soup can, is sliced straight down the middle?

A) Circle

B) Semicircle

C) Rectangle

D) Triangle

Answer · why

C) Rectangle

Rectangle is the shape whenever the cut runs at right angles to the base; through the middle it is as tall as the can and as wide as its lid. Slice th...

Q 04/05

Pi Day is celebrated on which date, chosen because the month and day match the first three digits of π?

A) March 14

B) April 13

C) June 28

D) July 22

Answer · why

A) March 14

March 14 is written 3/14 in the American style, echoing 3.14. The celebration was founded in 1988 by Larry Shaw at the Exploratorium, a science museum...

Q 05/05

When a billionaire walks into a small café, which measure of the customers' wealth barely changes?

A) Mean

B) Total

C) Maximum

D) Median

Answer · why

D) Median

Median wealth barely moves because it is simply the middle value once everyone is lined up in order. The mean would leap into the millions, dragged up...