Quests on Ruby

1.  How to implement Array#compact shortest way

2. 22520 - the smallest number which is dividing on all number from 1 till 10 without remainders. Which number are dividing without remainders from 1 till 20?

3. The sum of all natural numbers till 10, which is dividing on 3 or 5 is 23. What is the sum all natural numbers smaller then 1000

4. a and b - arrays. Junior developer has written 

   a = a+b 

   a.uniq!

  How to refactor this code?

5. Write latest 10 digits of 1^1 + 2^2 + 3^3 ... 1000^1000

Todo. Examples of solutions

Answers

1.  a-[p]. Correct answer is a-[nil] also. But 'p' it's a puts variable and it returns nil!

2.  232792560

3.  233168

4. a |= b

5. 9110846700

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