Thread:6f5e4d/@comment-26889090-20180523174714

Someone have brought in 10 pencils, the second person brought in 20 pencils, the third have brought 30 pencils and the fourth brought 40 pencils, as it goes on, the next person bring 10 more pencils than the previous so by the time 100 people are there, how many pencils will there be? 