Q 01/05

In the expression 2 + 3 × 4, which operation do you do first?

A) The addition

B) Whichever is on the left

C) The multiplication

D) It makes no difference

Answer · why

C) The multiplication

The multiplication comes first, which makes the answer 14; without an agreed order the same string of symbols could mean two different numbers, so eve...

Q 02/05

What is (2 + 3) × 4?

A) 9

B) 20

C) 40

D) 80

Answer · why

B) 20

20: the grouping symbols send 2 + 3 to the front of the queue, making 5 × 4, because such symbols overrule the usual order.

Q 03/05

What is the ratio of oranges to lemons, in simplest form, in a bowl of 8 oranges and 6 lemons?

A) 4:3

B) 3:4

C) 8:6

D) 4:7

Answer · why

A) 4:3

4:3 comes from dividing both parts of 8:6 by 2; the order matters, because 3:4 would describe a bowl with more lemons than oranges.

Q 04/05

A statement that two ratios are equal, such as 6:8 = 3:4, is called what?

A) A percentage

B) A product

C) A proportion

D) A permutation

Answer · why

C) A proportion

A proportion lets you find a missing number by multiplying across the known corners and dividing by the third, which is how a recipe is scaled up or a...

Q 05/05

The word 'percent' literally means 'by' what number?

A) Ten

B) One hundred

C) One thousand

D) One million

Answer · why

B) One hundred

One hundred is the 'cent' in percent, from the Latin per centum, 'by the hundred'; the same root gives a century its hundred years and a dollar its hu...