What begins with T, ends with T, and has T in it?

Can you count the number of lines in the below picture?

Considering the below equation:

V + II - VI = 10
IV - X + VIII = 20
IV - VII + VI = 30

Then, I + II + III = ?

What demands an answer, but asks no questions

Name a key which is hardest to turn.

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

Christina is older than Kareena and Karishma. Katrina is older than Karishma and younger than Kareena. If Kareena has a brother named John, who is older than Christina, who's the youngest?

A cricket has 6 legs, a squirrel has 4 legs and a spider has 8 legs.

In a local zoo, it was found that the total number of legs is 612. Also, there are equal number of each of the above animals/insects.

Can you find out how many animals are there in the zoo?