Solution:

5

Explanation
First three equation in the image can be written as :
a) 3 BED = 30
b) 2 BED + BUS = 40
c) BED + 2 BUS+ 2 TROPHY = 60

From equation a)
BED = 10

From equation b)
BUS = 40 -20 =20

From equation c)
10 + 40 + 2 TROPHY = 60

TROPHY = 5

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:

19

Explanation:
The children can purchase 19 chocolates in return.

Out of 77 wrappers, 75 will be used to buy 15 chocolates and two will be left spare.
The 15 chocolates will create 15 empty wrappers that can be exchanged to get three chocolates.
Three chocolates will return three wrappers which will help them buy another chocolate.
Now the wrapper from this chocolate and the two spare that were left earlier will get them another chocolate.
15 + 3 + 1 = 19

Solution:

This statement is true but only in a specific case i.e. if both of the siblings continue to live till the day the younger is as old as the elder one was during the time of their birth.

Solution:

10

Explanation:
Equation 1 + 9 + 11 = 1 can be derived from
One (o) + nine (n) + eleven (e) = one => 1

Similarly for equation,
12 + 11 + 9
Twelve (t) + eleven (e) + nine (n) => ten (10)

Solution:

She is near the trunk of the tree as shown below.

Solution:

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

Solution:

The women is a of short stature. She can't reach the upper elevator buttons, but can push is with his umbrella.

Solution:

He askes the god to beat him half to death.

Solution:

Everyone will done one day or other.

Abraham Lincoln era is too old and we expect most of them(if not all) to be dead by now.

Solution:

I + IX = X

The equation read from the other side becomes X = XI + I which is false.