Random Puzzles 

Workings

Hint
Cockroaches have 6 feet, mice have 4, and birds have 2. They each have one head.

Answer
35 birds, 5 mice, and 10 cockroaches.

Reasoning
Cockroaches have 6 feet, mice have 4, and birds have 2. They each have one head.

We can write down expressions for the heads and the feet, calling birds B, mice M, and cockroaches C.

Counting the heads:
(1)    B +  M +  C =  50

Counting the feet:
(2)   2B + 4M + 6C = 150

We are told that for every mouse there are two cockroaches so, C = 2M. Update (1) and (2) to give:
(3)    B +  3M =  50
(4)   2B + 16M = 150

If we double (3) we get:
(5)   2B +  6M = 100

We can now do (4) − (5) to give:
 10M = 50
   M = 5

So, we have 5 mice (and 10 cockroaches).

We can use M = 5 in (3) to give:
 B + 3 x 5 = 50
    B + 15 = 50
         B = 35

So, C = 10, M = 5 and B = 35.

Double-Checking
10 cockroaches have 10 heads and 60 feet.
5 mice have 5 heads and 20 feet.
35 birds have 35 heads and 70 feet.

The total number of heads = 10 + 5 + 35 = 50.

The total number of feet = 60 + 20 + 70 = 150.

Workings

Hint
The answer isn't very large at all.

Answer
There are four boys and six girls in the family.

If there were B boys, and G girls we know that Billy has twice as many sisters as brothers, so 2 x (b − 1) = g.

And his sister, Frankie, has one more sister than she has brothers, so g − 1 = b + 1.
    2(b − 1) = g       [1]
       g − 1 = b + 1   [2]

Using [1] in [2] gives:

2(b − 1) − 1 = b + 1

Expanding the bracket gives:

  2b − 2 − 1 = b + 1

Simplifying the left hand side gives:

     2b − 3  = b + 1

Add 3 to each side gives:

          2b = b + 4

Subtract b from both sides gives:

           b = 4

Using b = 4 in [1] gives:

    2(4 − 1) = g

           6 = g

Workings

Hint
Count carefully!

Answer
There are 10 letter Fs.

Sometimes the F in 'of' aren't always counted.

Workings

Hint
The 2^nd word begins with the letter B.

Answers
a-a-e = amaze (MZ) --ave = brave (BR) -uie- = quiet (QT) --gon = wagon (WA) p--ot = pivot (IV) vi-e- = vixen (XN) -ac-t = yacht (YH) --met = comet (CO) b--ep = bleep (LE) -u-ge = judge (JD) -lan- = flank (FK) -ra-e = grape (GP) bon-- = bonus (US)
This puzzle isn't guaranteed to have a unique answer, can you find another?