Can you find out the next digit in the following series ?

0, 0, 1, 3, 2, 6, 3, 9, 4, 12, 5, ?

Can you fill the blank with the correct number?

6 30 870 756030 _____

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

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

Prove that the below maths equation is true.

8 + 8 = 91

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

The cream is heavier than Milk. True or False?

Can you count the number of seconds in a year?

Clue: You need to bother about calculation.

Here is a mathematical expression that also secretly tells a movie name. What movie is that?

I have two sand hourglasses:
1. A 7 minute one and
2. An 11-minute one.

Using just these 2 sand hourglasses, how can I measure time as 15 minutes?