Brain Teasers and Puzzles 

Workings

Hint
Chloe has brown hair.

Answer
Name      T-shirt    Hair
Frankie   red        mousy
Lauren    yellow     blonde
Lucy      green      black
Chloe     blue       brown

Workings

Hint
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, …

Answer
71.

The first twenty prime numbers are: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71.

Workings

Hint
A little bit of algebra might help.

Answer
64 pounds.

The head weighs 24 pounds, the body weighs 32 pounds, and the tail weighs 8 pounds.

Reasoning
The trout is made up of the head, body and tail, H, B and T.

We are told that:

    T = 8

(1) H = T + B ÷ 2

(2) B = H + T

Placing T into (1) and (2) we get:

(3) H = 8 + B ÷ 2

(4) B = H + 8

Using (4) in (3) we get:

    H = 8 + B ÷ 2

(5) H = 8 + (H + 8) ÷ 2

Multiplying (5) by 2 we get:

 2H = 16 + H + 8

 2H = 24 + H

  H = 24

Therefore, by (2):

 B = H + T

 B = 24 + 8

 B = 32

Giving:

 H = 24
 B = 32
 T = 8

And a total of 24 + 32 + 8 = 64 pounds.

Workings

Hint
The animal begins with the letter F.

Answer
Flamingo.
--ute = flute
c--el = camel
st--g = sting
car-- = cargo