He wrote the word ‘THIS’.

Reading the answer the examiner understood that  the ‘student has good knowledge about taking risk,because the students himself taken the risk by writing only a single word in such an important exam’

Take the Coin 7 and 10 and place it besides 2 and 3 .Now take coin 1 and  place it at the top of 8 and 9.

Thursday.

According to the question one of them is lying other is saying truth.or both of them saying truth(Sunday).

Now suppose Lion is saying truth unicorn is lying.

Lion saying that it was lying yesterday. and this statement  become truth only  in Thursday.

and unicorn is lying.

Now Suppose lion is saying lie and unicorn truth.

unicorn says that it is lying yesterday too.But it become truth only in Sundays .But in Sundays lion also says truth so both lion and unicorn statement cannot hold on that day so this condition does not occur.

So only possible solution is Thursday.

Light a twig from the fire.

Use that twig to put the fire on the island some distance away from the already burning site.

now since wind is from west it will cause the  fire to spread east.

Start walking towards east through the area which completed the burning.

Now the fire will not reach you because the area behind you already completed burning.

(P.S:Now wait to die by starvation unless someone rescue you in time :)).

No. Anna cannot Pull up.

For Anna to do a thing that word should contain the letter ‘O’

He said that “My head will be chopped off”.

so if the man with ax decide to strangle him so his statement become false so his head must be chopped off.and if it is decided to chop his head the his statement become true then he must be strangled.

So the man with the axe cannot do any of his threat without making his initial threat false.So he kept pondering and other man walked over the bridge

Theoretically 
Nisha gave Rs20 as two Rs10 rupees.So the ice cream seller understood she needs strawberry ice-cream.Otherwise she will on give a single 10 rupee note.But Anuj gave a single Rs20 notes so the Ice cream seller ask him which ice cream he want.

In practical situation ice cream seller will ask which ice cream they want in both case because they may want 2 vanilla ice-cream for the 20 rupee .

JULY.

Cut the image in middle and look at the bottom part

Daughter is  10 years Old
Mother is 40 years Old