What do you answer even though it never asks you questions?

Remove two matchsticks to make the below equation correct.

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

I cannot talk, but I always reply when spoken to. What am I?

Three friends decide to distribute the soda cans they had among them. When all of them had drunk four cans each, the total number of cans that remained was equal to the cans each one of them had after they had divided the cans.

Can you calculate the total number of cans before distribution?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

In a school, there are four subjects. Seventy percent of students study English, seventy five percent of students study Science, eighty five percent of students study Mathematics and eighty percent of students study Spanish.

Can you calculate the percentage of students that study all four subjects?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

A game is being played where eight players can last for thirty-five minutes. Six substitutes alternate with each player in this game. Thus, all players are on the pitch for the same amount of time including the substitutes.

For how long is each player on the pitch?