Brain Teasers and Puzzles 

Workings

Hint
Convert the letters to positions in the alphabet.

Answer
M.

Reasoning
These are letters that occupy prime number positions in the alphabet:
B =  2
C =  3
E =  5
G =  7
K = 11
M = 13 *
Q = 17
S = 19
W = 23

Workings

Hint
Look at the lengths of their names.

Answer
James was sitting on the left.

Children with an even number of letters in their name sat on the right.

Workings

Hint
A little algebra might help.

Answer
Pineapple = 83p, coconut = 57p, melon = 62p.

Reasoning
If we assign the letters P, C and M to the fruits, and work in pence we have:

(1)   M + C = 119
(2)   M + P = 145
(3)   C + P = 140

Using (2) − (1) we have:

(4)   P − C = 26

And (3) + (4) gives:

         2P = 166
          P = 83

This can then be substituted back into (2) and (3).

Workings

Hint
What colour was the Stellar?

Answer
Dale Smith owned the blue Lunar.

Billie Richards owned the red Orbital.

Charlie Wilshaw owned the green Galactic.

Alex Stone owned the silver Stellar.

Reasoning
By (2) the Lunar was Blue, and was owned by Mr Smith.

By (4) the Orbital was Red, and was owned by Mr Richards.

By (5) the Galactic was Green, and was owned by Charlie.

Therefore the Stellar was silver, and by (1) was owned by Alex.
           Smith    Blue   Lunar
           Richards Red    Orbital
   Charlie          Green  Galactic
   Alex             Silver Stellar

By (2), Mr Smith wasn't called Billie, so it must have been Billie Richards, and Dale Smith.

By (5) Mr Stone wasn't called Charlie, so it must have been Charlie Wilshaw, and Alex Stone.
   Dale    Smith    Blue   Lunar
   Billie  Richards Red    Orbital
   Charlie Wilshaw  Green  Galactic
   Alex    Stone    Silver Stellar