Solution:

Concrete floors are very hard to crack

Solution:

1. Fill 5 liters jar ( 5l-jar:5, 3l-jar:0)
2. Transfer to 3 liters pail (5l-jar:2, 3l-jar:3)
3. Empty 3 liters jar ( 5l-jar:2, 3l-jar:0)
4. Transfer 2q from 5 pail to 3 pail (5l-jar:0, 3l-jar:2)
5. Fill 5 liters pail(5l-jar:5, 3l-jar:2)
6. Transfer 1q from 5 pail to 3 pail(5l-jar:4, 3l-jar:3)

Solution:

First Person: 3 full bottles, 1 half empty bottle and 3 empty bottles.

Second Person: 3 full bottles, 1 half empty bottle and 3 empty bottles.

Third Person: 1 full bottle, 5 half empty bottles and 1 empty bottle.

Solution:

7 minutes hourglass = p
11 minutes hourglass = q

Turn p and q.
P will finish at 7 minutes and then turn it again.
When q finishes (11 minutes), turn p again.
It will take 4 minutes for p to become empty.

The total time if you count is 15 minutes when p empties.

Solution:

The first step will be to cut the three tablets in equal halves and then put each half in two piles. Now, each of the two piles contains half of pill A and two halves of pill B (or one pill B). Now, take out one pill A from the bottle and cut it into half. Put the two halves in two piles.

In this way, each pile now contains two halves of pill A and two halves of pill B or 1 pill A and 1 pill B. You can now take 1 pile one day and the second pile on the next day.

Solution:

Here, there are two events that are independent of each other. Now, in such case, we calculate the probability of both occurring A and Bas:
P(A and B) = P(A) * P(B)
P(Pink) = 1/5
P(Pink and Pink) = P(Pink) * P(Pink)
= 1/5*1/5
= 1/25

Solution:

Since you can't identify which tablets are meant for which purpose, what you can do is take half of each tablet. In this manner, you will be able to get 1 of each tablet no matter what.

Solution:

Pick from the box that is labelled as 'chocolates and toffees’. Since it is an incorrect label, it must have either a chocolate or a toffee.

Suppose if you find a chocolate, then label it as chocolate. Now change the box that was labelled as chocolate earlier and label it as toffees and the box labelled as toffees to 'chocolates and toffees. This is because the one that was labelled as toffees (since it is labelled incorrectly) must have either chocolates or both chocolates and toffees. Since we have already found the box that has chocolates, it must have both chocolates and toffees.

Solution:

1st Bag = One Coin
2nd Bag = Two Coins
3rd Bag = Four Coins
4th Bag = Eight Coins
5th Bag = Sixteen Coins
6th Bag = Thirty Two Coins
7th Bag = Sixty Four Coins
8th Bag = One Hundred and Twenty Eight Coins
9th Bag = Two Hundred and Fifty Six Coins
10th Bag = Remaining Coins.

Now imagine any amount in your mind and you will find out that you can give any amount by just using the pouches (without opening them)

Solution:

Just form an equilateral triangle, planting trees at the vertices. Now find the center of the triangle and plant the fourth three on that point. In this manner you will form a shape of tetrahedron and all the trees will have equal distance between each other.