I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

What does this Rebus Picture mean?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

Find three numbers such that When we multiply three numbers, we will get the prime numbers. The difference between the second and the first number is equal to the third and second.

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

Open a Laptop which is password protected. Hint for the password is given as below:

1 mobile 3 books 2 Boards 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches

As a whole I am both
safe and secure.

Behead me and I become
a place of meeting.

Behead me again and I am
the partner of ready.

Restore me, and I become
the domain of beasts.

What am I?

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

Sachin bought a car with a strange 5 digit numbered plate.The water image of the number is 78633 more than my car number. All the digits of car number are distinct.

What is the original number on number plate?