Every words stands for unique digit that makes the arithmetic equation true

SEVEN + SEVEN + SIX = TWENTY.

What are the digits ?

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.

What work can one never finish?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

Can you calculate the probability of getting a sum of six when a dice is thrown twice?

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?

You are provided with a grid (as shown in the picture). Can you fill the squares with numbers 1-8 in a manner that none of the two consecutive numbers are placed next to each other in any direction (vertically, horizontally or diagonally?)

An evil man kidnapped someone and made them take one of two pills. One was harmless, but the other was poisonous. Whichever pill the victim took, the kidnapper took the other one. The victim took their pill with water and died. The kidnapper survived. How did the kidnapper get the harmless pill?