Raj wanted to type the first `200` natural numbers,how many times does he have to press the keys

Raj wanted to type the first 200 natural numbers,how many xx does he have to press the keys

Rahul wanted ot type the first 180 natural numbers. Find the number of times he had to press the numbered keys.

Find the sum of first 200 natural numbers.

Roshan wanted to type the first 190 whole numbers.Find the number of xx he had to press the numbered keys.

A typist starts to type the serial numbers of candidates in a list, upto 500. Minimum how many times he has to press the keys of numerals only ?