Random Puzzles 

Workings

Hint
There are fewer than 1,000 apples.

Answer
946 apples.

Reasoning
We know that (answer − 1) is divisible by 3, 5, 7, and 9.

If it's divisible by 9 then it's automatically divisible by 3.

So the number must be a multiple of 5, 7, and 9.

   [5 x 7 x 9 = 315]

Since these numbers share no other common factors, we know that the answer must be a multiple of 315 (+ 1).

Let's try 1 x 315 + 1: 316 ÷ 11 = 28.73, and this doesn't work.

Let's try 2 x 315 + 1: 631 ÷ 11 = 57.36, and this doesn't work.

Let's try 3 x 315 + 1: 946 ÷ 11 = 86, and this works, and is the answer.

Workings

Hint
A little algebra might help.

Answer
Width=40, height=20, depth=18.

Reasoning
If we call the height H, the width W and the depth D we have:
   H x W = 800

       H = 800 ÷ W (1)

   W x D = 720

       W = 720 ÷ D (2)

   H x D = 360

       H = 360 ÷ D (3)

Using (1) and (3) we have:
   800   360
   ——— = ———
    W     D

   800 x D = 360 x W

Using (2):
   800 x D = 360 x 720
                   ———
                    D

   800 x D² = 259,200

         D² = 324

          D = 18

Using (2), W = 40.

Using (1), H = 20.

Workings

Answer
                 Current   Previous
Brian Butcher    Plumber   Baker
Alan Baker       Butcher   Carpenter
Darren Carpenter Baker     Plumber
Charles Plumber  Carpenter Butcher

Workings

Hint
Find two numbers that multiply to 187.

Answer
There were 17 children, with 11 sweets each.

Reasoning
If we number the clues:
each child had more than one sweet there were more children than there were sweets per child
187 only has the factors 1, 11, 17, 187. Therefore, the only possible answers are:

   1 child, with 187 sweets each, which is not allowed by (2)

   11 children, with 17 sweets each, which is not allowed by (2)

   17 children, with 11 sweets each (*)

   187 children, with 1 sweet each, which is not allowed by (1)

Only one possible answer (*) isn't eliminated.