Brain Teasers and Puzzles 

Workings

Hint
A very common sequence, but in base 8!

Answer
13.

Odd numbers expressed in base 8, 11 in base 8 = 13.

Workings

Hint
Look at the gaps in the alphabetic position.

Answer
V.

Skip three and two letters alternately.

Workings

Hint
How many boxes of toys can 1 toy maker make in 5 hours?

Answer
Five toy makers.

Reasoning
How many boxes of toys can 1 toy maker make in 5 hours?
2 toy makers can make 6 boxes of toys in 3 hours
1 toy maker  can make 3 boxes of toys in 3 hours
1 toy maker  can make 1 box   of toys in 1 hour
1 toy maker  can make 5 boxes of toys in 5 hours

So 4 toy makers could only make 20 boxes of toy in 5 hours, and we require the extra toy maker to make the remaining 2 boxes of toys.

Workings

Hint
The answers are related to time.

Answer
60.

The numbers represent 100 years in a century, 365 days in a year, 24 hours in a day, 60 minutes in an hour and 60 seconds in an minute.