Solution:

The easiest method to solve this question will be to form equations.

From the first picture
Weight of Cat + Weight of Rabbit = 10 Kg ---- First Equation

From the second picture
Weight of Dog + Weight of Rabbit = 20 Kg ---- Second Equation

From third picture
Weight of Cat + Weight of Dog = 24 Kg ---- Third Equation

Add the first, second and the third equations.

2 (Weight of Cat) + 2 (Weight of Dog) + 2 (Weight of Rabbit) = 10 Kg + 20 Kg + 24 Kg
2 (Weight of Cat + Weight of Dog + Weight of Rabbit) = 54 Kg
Weight of Cat + Weight of Dog + Weight of Rabbit = 27 Kg

Solution:

Yes, some people are going get really tiny pieces but you were allowed for that right. Also, there is another way of doing it. Can you think of it?

Solution:

Align the toothpicks to form TEN. Use one toothpick for each of the lines.

Solution:

Steps:
1) Light fire on first bar from both the ends and second bar from one end.

2) After 30 seconds(when first bar gets completely burned out) , burn the second bar from second end as well.

3) When second run completely gets burned , you know its 45 seconds.

Solution:

If two widows, each having a son married the son of the other widow, and then by the consummation of marriage, both the couples had a daughter, all the aforementioned relationships will turn to be true.

Solution:

192 021

If you look at it as two-digit numbers you'll see:10 11 12 13 14 15 16 17 18 19 20 21

Solution:

Since the door is not visible in this picture, the bus is moving in the left direction.

Solution:

mother

We know from (3) that the youngest person was not the victim, from (4) that the youngest person was not the helper and from (6) that the youngest person was not the killer. The youngest person can only have been the witness therefore. If we make up a chart there are now three possible combinations:

Oldest person (father) H H M

Next to oldest (mother) V M H

Next to youngest (son) M V V

Youngest (daughter) W W W

(H = Helper ; V = Victim ; M = Murderer ; W = Witness)

We can work out from (5) that the father was the oldest, from (2) that the youngest person must have been the daughter. Therefore the next to the youngest must have been the son and the next to the oldest, the mother.

Solution:

7

Explanation:
8th is bald man head, check the video below.

Solution:

See the colored sticks in the picture. We have moved those sticks in the position given in the second image corresponding with the color.

Solution:

9

Explanation:
2 < 3 < 5
To find out the required number of candies, take one in place of the least number (i.e. take one mango candy) and then add all the greater numbers (i.e. three strawberry and five pineapple candies) to it.

Required number of balls = 1 + 3 + 5 = 9.