The vertices of a polygon are labelled with natural numbers from 1 to 2000 in increasing order. First we cross out the number 1 and then numbers 16, 31, 46...until one number is crossed out 2 times. What is the number and how many numbers are left uncrossed?

Dear Student

The number being crossed are in form 15k+1 firstly
Numbers will be crossed till 1995, Then 11 will come and the numbers will be like 11,26,41,56,.....1191
then it will be like 6,21,36..

Similarly,you can observe the coming pattern and find answers

Thanks