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?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

Forwards I am heavy, backward I am not. What am I?

10 people came into a hotel with 9 rooms and each guest wanted his own room. The bellboy solved this problem.
He asked the tenth guest to wait for a little with the first guest in room number 1. So in the first room, there were two people. The bellboy took the third guest to room number 2, the fourth to number 3, ..., and the ninth guest to room number 8. Then he returned to room number 1 and took the tenth guest to room number 9, still vacant.
How can everybody have his own room?

He runs but never walks. Murmurs, but never talks. Has a bed, but never sleeps. And has a mouth, but never eats?

How can you make a TV, a bed, a dog, and a car liquid?

The teacher told the student that if he told a lie then he will be expelled from school and if he told the truth then he still is expelled from school.

What can a student say to prevent his being expelled from school?

A solo dice game is played. In this game, upon each turn, a normal pair of dice is rolled and the score is calculated not by adding the numbers but multiplying them.

In a particular game, the score for the second roll is five more than what was achieved in the first roll. The score for the third roll is six less than what was completed in the second roll. The score for the fourth roll is eleven more than what was achieved in the third. The score for the fifth roll is eight less than what was completed in the fourth.

Can you calculate the score for each of the five throws?

You have $100 with you and you have to buy 100 balls with it. 100 is the exact figure and you can't go below or above the numbers and you have to use the entire $100. If there is no kind of tax applied how many of each of the following balls will you be able to buy:

Green Balls costing $6
Yellow Balls costing $3
Black Balls costing $0.10

Now, how many of each must you buy to fulfil the condition given?