Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?

Can you solve the below algebraic mathematical equation?

(J+O+I+N+T)3 = JOINT

Can you find out which number multiplied by itself will give the output as 12345678987654321?

All Marigolds are flowers.
Few Flowers are used to make colors.
Therefore, some Marigold are used to make colors.

True Or False?

Vin Diesel is pulling a theft and has planned to run away with all the cash kept in the safe. But the only way to open the safe is the 13 character password. He has a set of five clues given to him by a trustworthy source.

Exactly two of the below statements are false.
The password is contained within this sentence.
The password is not in this hint.
The password is within only one of these statements.
At least one of the above statements is a lie.

The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ?

Three ants are going up a hill, one behind the other. The last ant then says to the other ants, 'There is an ant behind me!'' How come?

On one occasion, A Boy collects 71 rupees in form of 20 paise and 25 paise. He collects a total of 324 coins.

Can you tell me how many 20-paisa and 25-paisa he got?

1. How can we put an elephant in the refrigerator?
2. How can we put a Giraffe in a refrigerator?
3. The king of the jungle invites all the animals to a party everyone comes except for one animal, which animal?
4. You come to a crocodile-infested lake, you can't go around it, you can't co under it and you can't go over it, how do you get across?