Brain Teasers and Puzzles 

Workings

Hint
One inch = 25.4 mm.

Answer
Millimetres in a mile.

Reasoning
One inch = 25.4 mm.

So:

1 mile = 1760 yards = 1760 x 3 feet = 1760 x 3 x 12 inches = 1760 x 3 x 12 x 25.4 millimetres = 1,609,344 mm in 1 mile.

And:

2 kilometres = 2000 metres = 2000 x 100 centimetre = 2000 x 100 x 10 millimetres = 2000 x 100 x 10 ÷ 25.4 inches = 2000 x 100 x 10 ÷ 25.4 x 16 = sixteenths of an inch ≈ 1,259,843 sixteenths of an inch in 2 kilometres.

Workings

Hint
There are 2.54 cm in an inch.

Answer
250 centimetres.

Reasoning
One inch = 2.54 cm.

And 1 foot = 12 inches = 30.48 cm.

So, 8 feet = 243.84 cm.

Workings

Hint
Think of chickens.

Answer
Don't count your chickens until they're hatched.

Workings

Hint
Work out how many each can eat in one minute.

Answer
53 minutes.

Reasoning
In one minute, Eddie eats 11 bananas (= 110 ÷ 10).

In one minute, Hugo eats 7 bananas (= 56 ÷ 8).

So in total, they eat 18 bananas every minute.

So it will take 954 ÷ 18 = 53 minutes.