Answer – 3

Explanation-

K = 1! + 2! + 3! …….. + 25!
Last digit of K = Last digit (1!) + Last digit (2!) + Last digit (3!) …….. + Last digit (25!)
Last digit (1!) = 1
Last digit (2!) = 2
Last digit (3!) = 6
Last digit (4!) = 4
Last digit (5!) = 0
Last digit (6!) = 0
.
.
.
Last digit (25!) = 0

Please note that Last digit (n!) such that n > 4 will be 0

Last digit of K = 1 + 2 + 6 + 4 + 0 + 0 + 0 … 0 = 3

Out Of the Box – Cut the cake Horizontally

Cut the cake Horizontally – Two equal pieces- Upper half and Lower Half

SOLUTION-   1 Measurement Only

EXPLANATION-
We will take,
1 coin from the first stack,
2 coins from the second,
3 from the third
and
so on.

In total we will have 55 coins.
If all of them were non-defective, they would weigh 550 gms.
If stack 1 is defective, the measure would read 549 gms.
If stack 2 is defective, you will read 548 gms.
and so on.

So by taking one measurement you can identify, which is the defective stack.

The nail will be at the same height.

Because – Tree grows at their tops.

Sun and Moon

Answer is a word “Name”.
That is,
It means if Arun is Meena’s father then Arun is the Name of Meena’s Father.

Total loss = Rs 1000

Transacton 1
Cost of perfume: Rs. 300.
Money he gives to I: Rs. 700.
Loss = Rs 1000
______________________________
Transacton 2
Money he Took from next shop finally: Rs. 1000.(PROFIT)
Money he gives to next shop finally: Rs. 1000.(LOSS)
It becomes = 0
______________________________
Total Loss

Loss in Transacton 1 + Loss in Transacton 2 =  Rs1000