Solution:

This

Solution:

84years old


The first equation (365g = 52s) can be approximated by
7g = s.

As before, the other two equations are
12g = m
g + s + m = 140.

The above system of 3 equations in 3 unknowns (g, s and m) can be simply solved as follows.
g + 7g + 12g = 140 or 20g = 140.
m = 12g = 12 × 140 / 20 = 84.

So, Grandpa is 84 years old.

Solution:

20
Just count the nines in the numbers: 6, 16, 26, 36, 46, 56, 76, 86, 96, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69.
Note: 66 contains TWO nines

Solution:

Ganpat had a black suit and a brown suit.
Harish had a brown suit and a pink suit.
Manoj had a white suit and a black suit.
Tarun had a pink suit and a white suit.

Solution:

Liquid state

Solution:

'2'

This single sequence in fact consists of two Series:
The first Series is 2-3-4-5-...
and
The second Series is 9-18-36-72-... .

Solution:

The second statement
(Two statements here are false.)

Solution:

Concrete floors are very hard to crack

Solution:

No time at all it is already built

Solution:

Let the sum of nine member (total) =x
and the age of old one=z
so its average 4 yrs before=(x+z)/10.
after 4 yrs let z be replaced by y.
so now avg=(x+4*10+y)/10

now (x+z)/10=(x+40+y)/10
so after solving it found
z=y+40.
so old person is 40yrs older than young one.