Puzzles to puzzle you
1. Apples and baskets.
Someone has mixed up the apple baskets. One of the baskets has apples that weigh more than the others. Here is what we know.
. There are 10 baskets containing apples.
. There are various amounts of apples in each basket ranging from 10 to 20.
. 9 of the baskets have apples weighing 100 g each.
. 1 of the baskets has apples weighing 120 g each.
. All the apples look the same.
You have a weighing scale measuring in grams, and an empty basket whose weight we know. It is late and the truck is waiting to take the apples to market. You only have time to make one measurement using the scales. Can you discover which basket has the 5 ounce apples?
From Mathsisfun.com
Ans: The key point is to realise that in only one weighing, we must include apples from all baskets. How to tell which apples came from which basket? Line up the baskets in a row and number them 1 to 10. Take one apple from Basket 1, two apples from Basket 2, etc, all the way to ten apples from Basket 10. So we have (1+2+...+10=55) apples in all. Weigh them all together in the empty basket. Now, if they all weighed the same, they would weigh (55x100=5500) g (leaving out the weight of the basket). But some apples are heavier. Now, we have to reason it out. Suppose Basket 1 contained the heavier apples. Then one apple would be heavier by 20 g and we would get a weight of 5520 g. If the second basket contained the heavier apples, we would get an extra weight of 2x20=40 g, or a total weight of 5540 g. If you think this through, you can tell the following: find the weight of all the 55 apples you have chosen. Subtract 5500 from this weight. Divide the remainder by 20, and that will give you the number of the Basket which contains the heavier apples. As an example, if we get a weight of 5600 g, then (5600-5500)/20 = 100/20=5. This means five apples are heavier than normal and these were taken from Basket 5, which has the heavier apples.
From Mathsisfun.com

2. Change the order
The diagram shows a cross-shaped box containing three numbered blocks
reading 3, 2, 1, downwards. The puzzle is to slide the blocks around the box until the numbers read 1, 2, 3 as you go down. How do you do it? And how many moves does it take?
From Mathsisfun.com
Ans: See the picture. It takes 8 moves.

3. What's in a name?
Sam's Mother has four children. They are called April, May, June, and ... What is the name of the fourth child?
From Mathsisfun.com
Ans: Sam! Did you get this one?!

4. Make the square
Can you fit the pieces to form a square? Maybe you can cut out the pieces first and try.
From Mathsisfun.com
Ans: See picture.