Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

Our product and our sum always give the same answer. Who are we?

Can you place six X (crosses) in below board without making three in a row in any way ?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

Can you make a fire with just a single stick?

John has played 50 ODI's and his average is 50. How many runs should he score in his 51st ODI, so that his average score jumps to 51?

Two in a corner, one in a room, zero in a house, but one in a shelter. What am I?

A wealthy man lives alone in a small cottage. Being partially handicapped he had everything delivered to his cottage. The mailman was delivering a letter one Thursday when he noticed that the front door was ajar. Through the opening he could see the man's body lying in a pool of dried blood. When a police officer arrived he surveyed the scene. On the porch were two bottles of warm milk, Monday's newspaper, a catalog, flyers, and unopened mail. The police officer suspects it was foul play. Who does he suspect and why?

Find the next number in the series.
1 10 24 43 67 ?

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?