Solve below rebus puzzle?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

I don't get anymore wetter, no matter how much rain falls on me.

What is red and smells like blue paint?

You have 10 balls with you. A friend of yours out of nowhere asks you to place those ten balls in five lines such that each of the lines has exactly 4 balls on them. He needs to check your intelligence. Prove him by doing the task.

Make the seating arrangement of 10 children in such a way that there are 5 rows with 4 children in each row.

John bought a new car. He has a habit of eating ice cream from a particular ice cream shop while returning home from office. Whenever, he eats strawberry ice cream, he faces no problem. But whenever, he eats chocolate ice cream, the car starts giving problem. At first, he thinks, it is just a co-incidence but when this awkward incident happens for 3-4 times, he reports this problem to the company.

The mechanic of the company checks but finds no problem at all. The next day, when he stops by to eat chocolate ice cream, the car again starts giving problem.

Can you find the possible reason?

Prove that the below maths equation is true.

8 + 8 = 91

A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it?

What is black when you buy it, red when you use it, and gray when you throw it away?