Saleh is delivering newspapers for his part-time job. he needs to deliver 30 newspapers and has distributed 10 so far.

what percent of total number of newspapers has saleh delivered so far?

He has delivered 33.3% of his papers. Think of it as a fraction 10/30. Now 100% is 30 papers. 1/3 of that, which is our fraction reduced, is where you get 33.3%. If you divide 100 into thirds (100/3), you get the percent.